this should be in AdSense hehe I find thi amusing. They have their own network, instead the advertise with their competition. wow to business.
Or maybe they are jacking up prices with Adwords, so advertisers come over to Yahoo Search Marketing. The people at yahoo are smart enough to have a plan, they would not advertise with Google if they didn't have a good reason to do it.
Funny but it could always be that someone (not Yahoo) is doing this as a joke. I bet it would make for some serious linkbait if it was posted on a blog