[edmundsauto]

Naive question, but if a winner had been found in a given niche, wouldn't there not be as much bidding competition and thus costs would go down?

Concretely: if I am the only pie baker in the world (I won), who else would bid against me for "place to buy pie"?

My unsubstantiated hypothesis is that google has gotten better at cross-promoting - so they could target people who like cake, increasing the market and competition for bids, making prices go up.

[jklinger410]

Incumbents often maintain large budgets to ward off competition. Competition wins enough to keep bidding, etc. If America is not full of monopolies, the bidding environment stays liquid. There is also the threat of using literal brand name targeting, or conquesting, which encourages your competition to run their own ads to keep you out.

I believe there are some agreements for larger corporations to continue to promote things even if it is not necessary. People with funny money can treat ad markets like billboards.

Another fucked up aspect is that the government often runs ads to promote its own policies.

Much like real markets there is sometimes unnatural activity that keeps it moving.