I think this is worth looking at
http://uk.youtube.com/watch?v=cUqXr9Jlhwc
It's funny, but I guess there is a point too. A multinational like Pepsi can use anyone to advertise themselves, yet they choose Gazza and chess.
There are some other examples you can check out
Topalov - SocGen
Anand - AMD
and of course the legendary Victor Korchnoi being defeated by a Cow!