MSN PPC on its Own Now?

I’ve found that the search volume for my Overture PPC campaigns has been declining. I also noticed that clients’ ads are not showing on MSN any more, which has been a long-time search network partner of Yahoo. I think it’s fair to say that MSN is on its own now in regard to PPC, with what they call “AdCenter”. As a matter of fact, I just visited MSN AdCenter and it says that they have just officially launched it today. Well I suppose its time to welcome a third major player in regard to PPC campaigns. I gotta go… and sign up!