In-game advertising revenue has been predicted time and time again to be a major source of revenue for game companies. Its good to see its being scrutinized a bit rather than being looked upon as the "cure all" for online costs, rising development costs, athelete's foot, etc.
I guess now might be a good time to pimp an old editorial of mine.
Anyone who's worked in an ad-supported business (like me) will tell you - there's only so many dollars to go round, there's lots of competition for those dollars, and not all advertisers will be interested in your product. Whie Stringer and Kotick, heads of large companies, might not be convinced that ads will be all that great for them, smaller companies should be on the lookout for the risks involved for them, not the least of which being losing control of their independance due to financial dependance on advertisers.