> Back then, you had a bunch of small business ad networks that you could choose from. There was a lot of consolidation. But they're still around. They're basi

> Back then, you had a bunch of small business ad networks that you could choose from. There was a lot of consolidation. But they're still around. They're basically that opaque network of algorithmic auctions you mentionned, in fact. If they can't display one of their direct clients' ads, they sell the spot to the highest bidder.