Imagine what competition in the search space would do for adword prices. I have no idea how one would go about breaking up google search, and the infrastructure/IP behind it. Or changing consumer habits, but there would be a lot of beneifts to everyone.
Adwords prices are based off the bids submitted - whether this is done through one centralized exchange or many competing ones makes little difference. Each search-based digital advertiser will end up charging the maximum it can while avoiding "vacancies".
