My friend tried to register one adsense account by using blogspot URL. But it is showing error message :- ‘URL can not contain a google host’
I thinks Google change their rules again, including for Blogspot subdomain, hope not 
Celebrating the little things on the net
You need 15 posts for blogger
and you can sign up directly through blogger, not through adsense
wow seems google bashing previously they used to accept blogspot urls fast