Here's a guess. Comcast isn't seriously considering text ads from Microsoft. In airing its unhappiness with Google, the cable giant is merely trying to improve its negotiating position. Much as AT&T has done with Yahoo. It's a perfectly sensible game for cable internet providers, and other media players, to play off the three big ad networks against eachother. But, when the three are by no means equal, the tactic is of limited use.

Google has so many more advertisers on its Adwords system, better distribution, and the most sophisticated algorithms for matching flush advertisers with appropriate search results: it can generate more than twice as much revenue per query as Yahoo; and, by some estimates, as much as ten times more than Microsoft.

The Redmond software giant is most likely already subsidizing partners such as Facebook, the college social network, in order to remain a player in the lucrative business of keyword advertising. But, in any extended price war with Google, Microsoft will lose. Comcast can be as unhappy as it wants, but there's still only one game in town. Google should call the cable giant's bluff.