It depends on a number of things, but mostly what type of players are you sending, and what site are you sending them too. If your sending players from a freerolls site, or a site that teaches the basics of poker – CPA is probably your best best (since the players you send are probably pretty poor). If your sending high calibre players – you would probably make more money of rev share. Sites where “cash games” are big, such as Party are obviously rev share candidates. Other sites are generally better CPA candidates, such as sites like Pacific who only allow one table to be played at a time (meaning less rake is taken per hour from most players then at other sites)