Apply google checkout

I want to apply google check out.
After I fill all table,it tell me must register google adsense.
I don't know why I need register google adsense.
I just want to be a Market publisher.
So I still fill the adsense table to apply.
It reply the mail many quickly.
But say this web site content is too less.
You can't pass the adsense register. 0rz