"In their seminal 1998 academic paper introducing the idea of Google, Page and Brin criticized advertising-funded search engines as “inherently biased towards the advertisers and away from the needs of consumers.”"
-- The times have changed.
-- The times have changed.
Everyone gets a free listing but if you want (typically) additional headings and (definitely) a big or bigger display ad you pay.
As a result if you are a general contractor that does kitchens and bathrooms and also sells plumbing fixtures as well you would have to spend the money to be listed in ads in all those categories.
Without having to spend money it ends up being confusing for consumers because it's like craigslist and inevitably results in people not being able to find what they want.
The "advertising funded" is actually a benefit not a detriment.
[1] I used the yellow pages to build a business from scratch that I actually sold. At the time I started I had no employees and there were established competitors (that didn't advertise) that did the exact same thing. The advertising is what made the business pretty much (in addition to price, quality service and all of that).
Note that this benefit disappears online, because of targeting. If you see an ad in print, you know the company had enough money to put that ad in front of thousands of people. If you see an ad online, it might have been targeted precisely to you, so the company might well be a scam. I wonder if there's a business idea in making online advertising into a more costly/believable signal.
Without having to spend money it ends up being confusing for consumers because it's like craigslist and inevitably results in people not being able to find what they want.
So Google without ads, when it first started, was worse than other search engines? Nope. The advertiser that bids the highest might not be the best option for the user at all
But there are some shades of Google leaning back that way, with "monitor-yellow" backgrounds, closing access to retail product search indexing, etc