[denton-scratch]

I can see how anti-trust comes into it, if they're abusing their market power.

But isn't this also straight fraud? I mean, running an exchange, and then lying to both advertisers and publishers about the price that was struck?

If antitrust is hard to prosecute because of the vagueness of "market power", why don't they just throw them in the slammer for fraud?

[mathteddybear]

I guess not really. The ad exchange is sort of an auction of auctions; for bare efficiency, every participating network submits only their top two candidates. This is communicated to ad networks; I guess, there is no obligation that the networks pass the bids of their advertisers unchanged. Google has some secret sausage there.

To Google Ads advertisers, Google says "you participate in a second-price auction, competing with other Google Ads advertisers and other networks; if you win you will pay the bid of the runner-up, which is the second highest bid from the Google Ads unless another network submits a bid in between" and that holds true.

To publishers, Google says "the price is determined in a second-price auction, every ad network submits up to two bids"

IANAL but it may be considered as an anti-trust, because it is the owner of the ad exchange who could decide if that obligation exists (regardless of whether it could be plausibly enforced).