> It was argued that this approach allows Google to charge higher prices to advertisers while sending less revenue to publishers such as news websites.

It could depend on how they 'limit the number of bidders'. If they sell seats to be able to bid, then the bids are lower to account for that, and publishers get a share of the bid, not the fee bidders pay. I'm guessing though...

You could limit to one mark and a bunch of planted bidders in an attempt to control competition. If you win with your plants, you get to pay yourself anyway.