Multiple Accounts

Is it possible to have an Account PER user type?

I.e. have an advertiser and a publisher.

The advertiser pays money into their account (Like Adwords but pre payment)
and the publisher gets paid from a seperate account (Adsense)

A user can be of both types, publisher and advertiser

These two Accounts can't be the same due to anything earned by the 'publisher' would be used by the 'advertiser'?

thanks