I freakin' love General Tso's chicken, but when I open up that book that says Children of the Mind on it, I want to read a book by Orson Scott Card, not look at pictures of delicious chicken.
However, in that actual example, I wouldn't really mind that much, since the book in question is in fact a library book which I am reading for free. I'd be willing to accept ads in library books. Audiosurf, however, is a game that I paid money for. Granted, it was on sale, but still, I paid for the full version of the game. And I'm being subjected to an ad for an unrelated game every time I play it.
What really gets me is the implicit hypocrisy. Us gamers are supposed to despise ads with every fiber of our being because they remind us that Republicans are right about capitalism, and a special circle of gamer hell is reserved for ads inserted against our will and/or without our knowledge into games that we paid for -- even when they don't directly interfere with gameplay (which this one does) and are optional (which this one isn't). So why does Portal get a free pass? If this were an ad for Microsoft or the Kardashians or Christianity or Mountain Dew or one of those other non-indie things that we're supposed to hate, there would be riots in the streets. FREAKIN' RIOTS I TELL YOU.
Actually, what actually really gets me is that it's a sucky ad. Either record more than one voice clip or only do it once. Whether or not it was effective the first time, it will be annoying the second time, and every time onward.
Anyway, I guess what I'm trying to say is I'm just really really sick of cake jokes. Screw you, gLADOS.