Will Glenn Beck et al scare advertisers into CNN's arms?

For the last couple years, CNN has been looking increasingly out of step with the cable news audience, offering up middle-of-the-road, milquetoast news in prime time as its competitors stocked their schedules with ever more strident political commentary. The result: a fall to fourth place behind surging Fox News, MSNBC and even even sister channel HLN.

But ratings are only useful insofar as they help to bring in advertising dollars. And now it looks like, just possibly, the tactics Fox and MSNBC have been using to drive viewership ever higher could be scaring advertisers away -- leaving CNN looking not so dumb after all.