Yahoo advertising in Google Mobile SEM

Yahoo SEM ad in GoogleA while ago I came across this ad by Yahoo while reading something on my iPhone. It's interesting that Yahoo is advertising it's pay-per-click, or SEM, in Google. They're basically paying Google for an ad promoting exactly the same service, but in Yahoo and Bing search engines.

It's like CBS running an TV ad in NBC to tell people they can run ads in CBS. Weird.