theweirdone

And you know, who is using GDPR as the gold standard and extending it globally? Uber. Yes, you read that correct.

Or, facebook(https://www.facebook.com/business/learn/facebook-ads-reach-e...) matches this cookie to your fb account in their system. Then making this information available across the browsers is trivial.

Now, to actually think of implementation, I can't even imagine the amount of data they need to store(and clear in LRU manner) to make this work.

As others have pointed out, it's an advertising technique called retargeting. Here are some of the technical details of how exactly it is done(Facebook's implementation might differ somewhat from this, but overall concept is same)

/* DSP - Demand side partner (Entity which works with someone who wants to show their ads) SSP - Supply side partner (Entity which works with some who have potential space on web to show ads) /

1. When you visited Amazon.com, one of the DSP associated with them drop a cookie on your system to uniquely identify you as a user. Let's call it cookiexyz. 2. When you end up on Facebook.com, their SSP also drops a cookie on you, let's call it cookieabc. 3. Now only thing remaining is to determine cookiexyz and cookieabc are same users. 4. To do that, SSP requests a bid from Amazon's DSP(among others). While doing that, it calls one of the DSP's url(bid tag) which sends cookiexyz in request headers and sends cookieabc in query params. This uniquely profiles the user which DSP stores in their system and next time user requests a bid again, they can serve them ads based on preferences based on cookiexyz. In other words, info that your looked at some shoes on Amazon.com

/ disclaimer: I work as a dev in one of the Advertising partner for Yahoo and Bing. */

My bad. Should've tested it on browsers other than chrome. It is working now on Safari btw, please check it out if you get a chance.

Any xkcd fans here? I made a progressive web app for xkcd, with all the usual features of a pwa(offline loading, installable etc.) I made this to learn about service workers and performance optimisations, so comments and feedback are welcome.

Did you try this one: https://react-hn.appspot.com/

I want to be more socially active in 2017. I graduated in 2013 , got a dev job and since then been living in a virtual world w/o any interaction whatsoever with people outside of professional environment. In 2017, I want to break this trance, get to know the real world and probably get a girlfriend. :)