Doesn't really bother me too much, unless it either a) interrupts games, or b) gets in the way of my theme. Ads are a fact of life -- they're in magazines, on the sides of buses, down the side of your Google search, before your movie at the cinema. You learn to tune them out pretty quickly, I find.
Now, if they, say, interrupt a TV show that I've downloaded off of Live with them? That'll pretty much guarantee I never check out the video section ever again. It's all a matter of how they're handled.