why not make one site - just one. make it in the best way you know how to, then learn through it? i can guarantee taking the time to learn to do one thing right will be more valuable than doing 4 things half-assed.

btw, i know a couple guys who don't own any paysites yet make 50 or more sales per day on their sponsors. they focused on learning traffic, and they kick my ass and also the asses of a large number of small and medium paysite programs' asses. most paysites never make that much - there are lots of ways to make money in this business that don't involve having to own and cut up content and deal with updates and members.