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> Sure, you're never going to know exactly how many people you advertised to would have organically, eventually found your product and bought it. But that honestly doesn't seem that important compared to the other metrics...

Wait, why wouldn't that be important? It seems like the most important question since it asks whether advertising has any significant impact at all.

It's critically important for adtech companies' customers, since it's an essential part of determining return on investment.

But it's also critically important for both adtech companies and data scientists who work in the space to direct people's attention away from those sorts of metrics. You generally don't want to call the attention of the person who signs your paycheck toward the fact that it's all but impossible to really know for sure if your service has delivered them any net benefit.

This is creeping pretty close to the legal definition of fraud.

But advertising has had a fair amount of safe-harbor carve-outs for over a 100 years or so that are not available to other industries. So it is no surprise it continues today.

edit: I hate to say it but the auto-downvoters here on HN are approaching reddit levels. Everything I said above is true.

This is the industry whose job is to manipulate and deceive people. It should surprise no one that, if they do that to others, they'll do that to themselves as well.

> "edit: I hate to say it but the auto-downvoters here on HN are approaching reddit levels. Everything I said above is true."

It's not that you're wrong, it's that you're boring.

"I knew this years ago, look how my cynicism is superior to your naievite" is a boring comment to read. You could explain why you think this is any closer to fraud compared to selling anything else and claiming it's the best in its class, or what safe-harbor carve outs by whom, or why they matter more than other effects, or what you think should be done to change them, or anything more substantial than "I'm not surprised". Oh aren't you? Great, cool story bro. Except it's not /even/ a cool story.

It's old man "get off my lawn". It's every tech forum's old-man status grabbing which is now approaching Reddit /r/SysAdmin levels on HN. The only question is whether aggressive downvoting can curb its growth here before it gets a choke-hold.

Please don't cross into personal attack and name calling. It only makes things considerably worse.

https://news.ycombinator.com/newsguidelines.html

I will rephrase as "your comment is boring" rather than "you're boring" in future; my intent was to describe the comment and not to attack the author's person.

That would certainly be better.

It's sad to see the downvote culture come here. Downvoting is meant for removing contributions that don't add much to a discussion, not for indicating whether someone agrees or disagrees with you. It seems to be a norm that is spreading though, sadly.

It would appear jodrellblank is perfectly demonstrating how to misuse the feature, by calling you boring. Not exactly the kind of attitude that we want to have around here.

The downvote button should be replaced with an "off topic" flag. If downvote is opposed with upvote and upvote is understood to mean "I agree" or "this is informative" then downvote would be expected to mean "I disagree" or "this is bunk". It's semantically misleading.

> The downvote button should be replaced with an "off topic" flag.

I hope not. Some of the most informative, useful comments I've seen on Hacker News have taken the form of wild tangents.

I do see where you're going, though, that if "I agree" is sufficient cause for an upvote, then it's only reasonable that a vote in the opposite direction should be allowed to carry the opposite semantics.

It's just that, from a purely social standpoint, that's not actually how human beings typically think, feel, and react. Perhaps it could be that simple on the Vulcan version of Hacker News.

Oh for sure—wild tangents are fine as long as they're unpredictable, which is what makes them interesting. The offtopicness we try to avoid are generic tangents, the kind where people get sucked into the same argument about some topic that they always get sucked into. Those are the black holes of internet forums—it's best to steer clear.

https://hn.algolia.com/?dateRange=all&page=0&prefix=true&sor...

https://news.ycombinator.com/item?id=117171

To be clear, "off topic" here's just an example. My main point was the semantic implication of a downvote - I've seen the argument of "downvotes are not meant for disagreement" expressed here previously.

> It would appear jodrellblank is perfectly demonstrating how to misuse the feature, by calling you boring.

I don't have an opinion on what "correct" downvoting culture would be, one way or the other, but - if you say "contributions that don't add much to a discussion" should be downvoted, then isn't a "boring" comment precisely one that _should_ be downvoted?

I also always thought that downvoting should be reserved for low quality comments, but I had been corrected and even dang said:

Downvoting for disagreement has always been ok on HN.[1]

I don't really like it, but it has always been the case on HN. The question is if the community voting behavior has actually changed.

[1] https://news.ycombinator.com/item?id=17666145

Downvoting for disagreement is okay? That is new to me. Well okay then. I will proceed accordingly.

Thanks.

From somewhere in the warren of links to dang posts I traced out from there:

> I think people have the wrong idea about HN downvotes because they think Reddit rules apply to HN.

That one gets me, because I had previously assumed that downvoting for disagreement would be a standard Reddit thing, but that HN's community is supposed to strive toward a more "we're all mature adults here" kind of community standard.

That's not true. Downvoting for disagreement has been ok on HN from the beginning.

I realize people have strong feelings about it, but that's because of the psychological intensity of the mechanism. There's no way HN would survive without downvotes, despite the fact that not all downvotes are fair. It's a critical part of the immune system.

https://news.ycombinator.com/item?id=16131314

I have noticed the same thing over the last four or five months. I’ve been curious if a voting ring has sprung up on HN or maybe a COVID impacted demographic suddenly has a lot of time to patrol the site, or if it’s something else. It would be really interesting to have some anonymized voting data to analyze and see how downvotes map to accounts, geography, and economic trends over time. Though voting data must be relatively huge compared to content and I bet it gets discarded after items close to replies.

> advertising has had a fair amount of safe-harbor carve-outs for over a 100 years or so that are not available to other industries.

What safe-harbor carve-out existed 30 years ago for advertising that another industry might have wanted something similar on?

Lying to consumers. Puffery is the legal term of art.

The "reasoning" allowing advertising/advertisers to lie is that it is assumed consumers do not believe it.

It is not fraud to distract from evidence that your product might not work. It is fraud to claim your product works if it doesn't.

Therefore ad companies are not going to try to prove that their product doesn't work.

Common law fraud is hard to prove in the US.

All of the elements listed below must be proven. However, some of the comments here describe behavior that comes pretty close.

(1) a representation of fact; (2) its falsity; (3) its materiality; (4) the representer’s knowledge of its falsity or ignorance of its truth; (5) the representer’s intent that it should be acted upon by the person in the manner reasonably contemplated; (6) the injured party’s ignorance of its falsity; (7) the injured party’s reliance on its truth; (8) the injured party’s right to rely thereon; and (9) the injured party’s consequent and proximate injury.

Please don't break the site guidelines by going on about downvotes. I know they suck, but bilious addenda about downvotes also suck, which is why users here are asked to restrain themselves from posting them.

https://news.ycombinator.com/newsguidelines.html

Apart from taking threads badly off topic, such complaints usually end up as uncollected garbage, since often the most unfairly downvoted comments end up getting corrective upvotes from users.

https://hn.algolia.com/?query=corrective%20upvote&dateRange=...

Does advertising create an increase in buying your product. That’s the most important question.

At least with ecommerce one can track users that have seen and/or clicked on ads with what they have purchased and return on ad spend can be calculated.

But yes, the question still is: does it raise intent or did the user already want the thing, googled it, and clicked on the first result (which is your ad, above the organic results that also lead to your online store)?

The fundamental problem with this is that if I bought your product, it's because I was looking for your product after doing a decent amount of research which meant I was on a bunch of retargeting lists and you've wasted money on me. I have never to my recollection purchased anything because of an ad. If I have clicked through an ad, it was simply because it was the quickest way to get to the website/product.

There is a role for advertising because Google polluted their organic search results with Ads making it harder for you to find what you want and forcing you to compete for the top Ad spot. I realize that I can only speak for myself, but I have never seen any evidence that advertising works and I've worked in ad tech.

It's pretty clear to see direct causation when using ads to promote your product. Promote your product using ads for 1 month, then turn off ads and see how many sales you get. For a majority of e-commerce, you'll see a substantial drop.

You've researched every item you buy in your weekly shop? You've never bought anything on a whim, or a gift for someone else?

If you are sinking $100M in, I sure hope it’s having some effect.

You're also bidding for eyeballs. An established player might want to scoop up the most relevant keywords forcing competitors to at least price match, effectively starving them either of views or cash

There's still value in getting people to buy now instead of maybe buying later.

The thing about the "advertising doesn't matter" argument is that there are situations where advertising absolutely matters - when a company is just starting out and there's no way they can get organic referrals, when the public is unaware of their existence, etc.

Moreover, most companies started small at some point so advertising and maintaining advertising made sense up to a point.

And if we look at those companies where maybe advertising actually doesn't help, companies that have reached a level of success where organic referrals and public awareness drive most of their business. And they're ongoing businesses that probably reached that level through advertising and have money now to use for that.

But not only are they already advertising but they don't if their word-of-mouth/public-knowledge presence will last indefinitely, they don't know if just word-of-mouth would let them control their image, would stand-up against future competitors ads and so-forth. So, even supposing you could show advertising didn't offer any immediate increase in customers, continuing to spend on it doesn't seem to me as irrational as it sounds.

This is the point that a lot of people are missing

Uber shows up in the news and in conversation every day. Most people have heard about it by now. Very few people are going to install it because they saw an ad.

Not the case for your neighborhood "Bob's Burgers" or "Uber Competitor" or some other new company. Or for specific marketing actions of known companies (promotions, new services, etc)

Furthermore, many of the people who say they hate advertising also hate PR and other sort of marketing campaigns. So presumably their theory is that people should build something and just hope people will discover them somehow.

It's a subset of the misunderstanding of "meritocracy" that defines it as "how well you can do at a narrowly-defined task" as opposed to the practical definition of "How many people know how well you do at a narrowly-defined task."

Our industry is shot-through with idealists who believe meritocracy should be the former, when in reality it's always been the latter (and always will be, unless someone can invent omniscient humans).

Well, and arguably, "How many people know how well you do at a set of tasks that are broadly relevant to them."

> Furthermore, many of the people who say they hate advertising also hate PR and other sort of marketing campaigns. So presumably their theory is that people should build something and just hope people will discover them somehow.

Could it be that people simply don't like being interrupted and having their time wasted, whether it's by ads, marketing or PR? Just because you have a business to grow shouldn't give you the right to waste my time.

Also Uber would benefit from a higher price of advertising for upstart taxi companies.

That still doesn't address the GP point, advertising doesn't matter if you can get customers coming to you organically. Business size changes the odds of that, irrespective of that if the customers would have come to you anyway (and there are ways to know this!) then the ad spending was largely a waste.

You misunderstand what advertisers are trying to achieve. It's about Brand Awareness. They just want their brand out there and seen. Even click-throughs aren't as important as they once were. Coca-Cola still advertise when they probably don't need to.

I understand the distinction between advertising and building brand awareness. It doesn't sound like Uber was doing the latter. It also doesn't take away that if you're advertising to an audience who'd have come to you anyway, you're wasting your money.

Brand awareness must also be maintained, just like human relationships! How often do you tell a loved-one that you love them? Is once enough, because going by your stance, since you've told them already once before you shouldn't need to do it again!

I don't think there's a large "advertising doesn't matter" camp. For most the real question is around the efficacy of certain types of ad buys, ad targeting, SEO efficacy and the amount of fraud in the system.

The real problem is that for large companies with brand awareness they're starting to find a lot of their spend may not be generating revenue. Ebay in the Freakonomics podcast turned of about $100M in ad spend with no loss of revenue. But smaller, companies usually don't have the staff/knowledge necessary to know how and where to use their ad dollars.

>when a company is just starting out and there's no way they can get organic referrals, when the public is unaware of their existence, etc.

I don't think I ever saw a Whatsapp or Telegram advertisement in the first few years of their existence. There's a lot of software in particular that gets around by word of mouth alone.

Necessity for advertisement seems correlated to how unclear it is what advantage your product has for the consumer. If you make something that's like X but twice as fast or twice as cheap you don't need advertisement.

Ad spend by incumbents will also drive up the price of advertising in general since it's a limited resource, making an uphill battle for the smaller competitors where it matters. It's another moat.

Depends on the timeline. If for financial (or other) reasons, they need to "reach the audience ASAP", then sure, advertising is likely to be a good or even required move.

But if they want to exploit a more organic growth curve, and are in a financial position to do so, then advertising isn't so useful.

Ardour is a cross-platform DAW that has been around for 21 years. Every 2 minutes somewhere in the world, someone starts a version they got from us. We've never advertised.

Maybe the person is referencing how difficult it is to determine the value of the counterfactual? If it were possible to determine I imagine people would really want to know.

I think the implication here is "that honestly doesn't seem that important" because the expectation is that the number of people who would find you anyway would be a small number compared to a well-run ad campaign, at least over timeframes startups care about.

Having worked with a decent number of small teams without a lot of brand recognition, ads bring in a lot of customers: it was pretty obvious in our metrics when we ran ad campaigns vs when we didn't. Sure, eventually a few of those people may have found their way to us somehow anyway, but there was a step change in volume from ads. At least in my experience, the idea that ads have no significant impact is not really supported by the evidence. I assume that's what the OP meant by it not seeming important: they're working under the assumption that "do any ads do anything" is clear and you don't need to prove the worth there — instead you need to prove which ads work better than others, and cull the ones that don't perform well (which will also help save you from scammers).

One could argue that advertising for large brands with name recognition could be less valuable. I don't really have data or experience to know that one way or another, but in a competitive market that seems a little hard to believe. Tesla is an interesting counterexample, but I think it may be in part due to the EV market in the US not being particularly competitive; no one makes attractive, mid-priced cars with long range other than Tesla, let alone having an established charging network for road trips. And Elon's antics are, tbh, a form of marketing in and of themselves; "all press is good press."

Edit: I wrote the above paragraph badly. I can definitely believe ads are less valuable if you're a big brand vs a small one. But I'd be surprised if they're useless, at least in a competitive market. People don't have infinite money, so if they're looking to buy X and an ad for X from your competitor pops up, it seems reasonable to me that some percentage of the time your competitor would make the sale and thus you wouldn't, even if organically that sale might've gone to your company instead.

Also, I wouldn't argue that even small companies need ads — just that they do seem to be effective at increasing the volume of people interested in using your product at a given time. That may or may not be necessary/useful depending on your situation. I have been on teams where we intentionally turned off ad campaigns because we learned what we needed to learn from the cohort of new users, and now wanted to improve the product based on their feedback before spending money on more ads.

>One could argue that advertising for large brands with name recognition could be less valuable.

It is without a doubt, and this is what the Freakonomics advertising episodes are mostly about.

Yeah, I wrote that badly. It's easy for me to believe they're less valuable. I really meant "One could argue that they're useless, but that seems hard to believe in a competitive market."

> Sure, you're never going to know exactly how many people you advertised to would have organically, eventually found your product and bought it.

This is typically an order of magnitude less than the attribution figures stated by digital marketing experts. A/B test is the right method to use, but the crucial thing is you need an earmarked population to see zero adds over your attribution window, since what you care about is impact on incremental sales, rather than incremental click likelihood.

There is a long econometrics literature on this and it is not a fussy technicality, the figures typically differ by 10x +.

Instagram definitely does this. I'm part of the magic cohort who never see any ads :)

Did you actually read the linked tweets?!

Uber turns off a shitload of ad spending, nothing bad happens to new user acquisitions.

I'd say there are about a million better uses of a million dollars than just pissing them away on a scam.

There’s an interesting question there about when this form of advertising becomes obsolete.

Uber is in a very different position than many other companies. Anyone who browses the internet with regularity is already aware of their existence and probably just needs the right set of circumstances to come together to make Uber useful to them.

I suspect the results would be different if Uber were earlier in their adoption curve, but maybe that’s not true either. Maybe they’d be ignored for different reasons at that time.

Likewise, I probably haven’t seen an ad for coca cola or kleenex in a while. Once a brand is ubiquitous to the point where soda becomes coke and tissues become kleenex in the lexicon, it feels like ad spend is wasted.

Brand advertising is different. It is there to remind people about the brand. Companies do it because they have the analytics that show that it works.

They mostly do it from inertia, how well it works is a separate question. Historically you can find many examples of hugely successful advertising campaigns, it’s much harder to quantify the negative.

I think both Uber and CocaCola has a lot of work to do until I like any of them. I like CocaCola as a product though. Never tried Uber. For example I really like some Nestle products, but try to avoid them because of their bad company/brand reputation, even if their product is both cheaper and tastier I buy from a competitor instead. Whatever a company stands for and how they act will affect their brand.

Coca Cola spends billions on ads.

8 million views: https://www.youtube.com/watch?v=yg4Mq5EAEzw

>8 million views

So, less than a viral cat video?

Is it really christmas time, if there are no cocacola-trucks-driving-to-town ads on tv?

Paying for crappy app installs on shady sites is not really advertising.

What they should have done was a proper hyperlocal SEO campaign like Firestone Gieco, and Mc Donalds do.

There's a huge difference between a company that is widely known for being the app for ride hailing and a small company trying to get eyes on their new product.

Well, Uber is known to everybody by now. To the effect that "to Uber" is even kind of a verb/noun.

Also people either need a hired transportation or not. If they don't have a car or don't want to mess with the traffic and need to go somewhere, it's either Uber or Taxi usually.

It's not like Coca Cola, which is well known, but people could do without it (unless addicted), so needs to constantly nag people.

And it's not like some new product, which without advertising nobody would even know it existed.

In fact most of Uber's existance its operation has been 100% advertising (spending VS money to offer cheap rides and expand and gather "eyeballs" and "customers" without a profit). In my book, customer acquisition without profit is another name for advertising.

So it doesn't sound strange that it could do without advertising today.

But what if there were 3-4 strong players in the same, each eating in Uber's market share? You'll see how fast they'd found advertising indispensable again...

Literally lighting them on fire in a cold office to help provide some BTUs would’ve been a better use of that money, since at least that would offset spending somewhere else.

>but you can also measure against SEO traffic with a high degree of certainty.

None of these benchmarks distinguish between the selection effect (clicks, purchases and downloads that are happening anyway) and the advertising effect (clicks, purchases and downloads that would not have happened without ads).

You can fix this by dividing the target group into two random cohorts in advance: one group sees the ad, the other does not. Designing the experiment thus excludes the effects of selection.

When you do this experiment correctly, you find out that ads have low effect or are not cost effective (as eBay discovered).

> You can A/B test ads pretty easily

A/B testing ads is a complex matter. you can A/B traffic and conversion easily, but a lot of established companies with fierce competition fight for mind share, not direct conversion; for that, you have both awareness effects (user won't forget about coca cola if they don't run ads for a month, and an ad that doesn't directly convert but increase awareness still has value) and coverage synergies (the number of repetitions in a day will increase coverage non linearly and the amount of channel repetitions will increase awareness more than a single channel view, even if it doesn't convert immediately)

> All big companies do this.

Except Uber, apparently? Or would the method you're talking about not have discovered that something fishy was going on? (I don't work with ads so I don't know the limitations of the type of experiment that you're talking about)

It would work for some of Uber's ads. From the article, it looks like they were frauded mostly by in-app ads. And they were paying for installs - not actual trips.

So, no, Uber's advertising here is a little different than (I think) the majority of companies. They are mostly paying for installs rather than sales / conversions. A lot of newer "app" companies could be in similar situations.

Though, honestly, this seems like a massive fail on their analytics team for not figuring this out earlier. They should have been able to see that all of these "installs" from certain advertisers were not leading to trips.

In fact, it says they turned off 66% of ads. They didn't randomly turn of 66% of ALL ads. They turned off this TYPE of ad, which they failed to earlier recognize was ineffective.

Step 1) assume your ads won't work.

Step 2) have enough analytics / logging in place to convince yourself the ads do work.

Step 3) if they don't work, turn them off.

Looks like they skipped step 2 - which honestly, is not uncommon for a fast growing business - even if they are huge and already make a lot of money.

What they found isn't even what people are discussing. They found that certain networks they were buying ads from were almost 100% fraud (which is pretty well known).

Instead, people here seem to be discussing that most online advertising is fraud, and/or that there's no way to prove it's effective. That is absurd.

Hang on though, in the linked thread they said that the fraud was incurred at the point of real users signing up for uber -- when they type uber into the app store search (e.g. an organic install), the ad network fraudulently takes credit for it at that point. So "enough analytics/logging" would not do the trick here - I think they would have noticed if a certain type of ad wasn't leading to trips, as you are pointing at.

You can definitely measure 'lift' - though it's far easier with online only sales.

For sure it's harder for say Gucci to measure incremental cross-platform lift but any good large brand spends big money trying to parse it out

One example way to get some value measurement would be Facebook's powerful tools. Beyond a basic 1:1 audience 50/50 exposure test, Facebook also lets you upload offline sales (or use their pretty effective pixel for real time online sales) and then feed into their system. Using the data your purchase data FB matches to ads delivered and you (with PII but also purchase value and frequency). Then the advertiser can define lookback/conversion definitions to get a measure of incremental lift. E.g. those who clicked ad bought __ right away, those who viewed ad within 1, 7 or 28 days bought __.

For what it's worth the adtech forums I participate on view Uber as incompetent idiots on this issue (which has been reported on like last year) - all they had to do was measure beyond the initial install for say did these installs actually pay to ride...

Install fraud from SSPs and resellers is huge, doing this basic measurement and quality control is the reason Facebook and Apple have huge and growing app install business. Though TBD on Apple fucking over Facebook and keeping the attribution for themselves alone with their new privacy features

Across this and the other[0] highly active digital ads post, there's 3 interesting forces at play:

a) technologists screaming "ads are literally the worst societal cost, like ever" who don't want to understand the industry

b) advertising folks taking up arms to defend their shamanistic, money-printing machines without statistics (Reason No. 7 will SHOCK you)

c) A tiny, tiny group of Mandalorian-like voices who have a necessary statistics AND industry understanding who are being drowned out

(this is in jest, but I double-dare you to say it isn't at least directionally accurate)

Other commenters have mentioned it throughout this whole comment thread as "incrementality tests". Amongst other approaches, this is the way.

Freakonomics severely lack the industry understanding. Listening to the podcast was like hearing how HTML is a programming language from the kid in week 2 at code camp. Then too the article, all the issues with Uber was just doing a bad job of managing their ad spend and they can fall into group B, noted above.

The baseline of this work is a control group who see no ads and then you build your tests from there that factor in channels, cohorting, and other components to get a statistically significant outcome. Yes, this will get more challenging with upcoming privacy changes (IDFA removal, et al). However, the last 10 years this wasn't a problem and I'm sure the corporations in the identity resolution business will hand-shake on a bunch of 2nd party data deals that just move the deals done in broad daylight around identity tracking and audience creation to the alley. Further, any advertising that is tied to an already known customer is able to be backed into at an audience level with login and cookie data. Even Pi-hole users may not be exempt here.

To finish with some constructive advice:

1) Advertising is not a synonym for marketing. We're only talking about advertising in both HN threads.

2) Every industry has high and low quality. Pareto's principle should be aggressively applied to where one spends their budget in the cesspool that is the Internet.

3) If you're ever seeking an agency to provide advertising services and they don't have a qualified data science or statistics leader (10+ years work experience, degree in Stats/Math/Econ, an MBA, or similar), run. Run from those shiny-shoes gurus. Channel your inner Usain Bolt and run.

0. https://news.ycombinator.com/item?id=25620707

So how much ad spending is going to 'dubious ad networks'?

Are they easy to categorize? Or is it a big secret what's dubious and what isn't?

This is all discussed in the podcast.

There’s no revenue change even after testing (when you tack on costs of ad delivery).

It can happen that an almost certainly bogus scientific field persists for decades using state of the art research methods and no bad faith on the part of the researchers (any bias they introduce is probably not conscious). https://slatestarcodex.com/2014/04/28/the-control-group-is-o...

A/B testing is... not a state of the art scientific research technique. Moreover the companies that provide the tools to do A/B testing are the same companies that sell you access to advertising space. I'm not saying that it's a common practice to defraud A/B tests, I'm saying that the fact that adtech companies have chosen to enable that research methodology out of the set of all methodologies they could offer suggests that we should expect, before seeing the results of any A/B trial, that the results will tend to favor the adtech narrative.

I don't think that people in the adtech space believe they're selling a bogus product, but I do think they wouldn't want to know if they were — they have a good thing going.

If you're employed in adtech you're mostly fine, skills transfer. If you're invested in adtech, do what you can to diversify away. Advertising is overvalued to some extent and that bubble will burst at some point or other. The question is just how much actual value advertising provides, how much will remain when the bubble bursts.

"You can A/B test ads pretty easily, and this is quite common. With some degree of statistical certainty, you can tell how one ad performs to another."

Nope.

You need a unique id for an AB test AND apple wont give this to you. No company is going to give you a click/tap id. Android might. This is so inaccurate I don't know where to start. Apple has turned off all unique ids that work across an AB test [1] cross platform. You would need on the ground mobile ad experience to know this.

https://www.invoca.com/blog/what-is-idfa-and-why-apple-kille...

For native Android you 100% have access to an Android "device id". I set this up on an Android app we delivered. There's even companies that pay other Android apps to host their code inside the app, co-related that ID to other data available to the web (e.g. IP address, installed fonts, etc) to provide a very good guess of a user's device id via the web.

Apple had something similar, but you're right they're starting to turn it off. In my past life in Adtech we noticed the click through rate of users with Android user agents were a lot higher on certain campaigns than iOS users for this reason.