without speaking about pap4 in particular, the expensive programs do amazing things, and lots of them. it takes hundreds of hours to develop a program like that and tons of time to keep it updated and adding new features.

the stats in NATS and probably in MPA can help you make more money. they'll show you things you probably didn't know about your sales. they'll also allow you to answer virtually any questions your affiliates have about their traffic and sales.

NATS and MPA also allow you to create several pricing options plus popup and no popup tours on the fly. they're also designed to work with adult-specific processors and have some fraud control built in, as well.

pap4 may be a great program - they don't give the level of detail that i'd want to know before trusting my money to any program, adult specific or otherwise. they don't mention how often they do security updates

what i noticed as i checked their site is that they had a third party do their video tutorial (and the narrator isn't very good), that their graphics and layout look either old school or rudimentary, that a lot of the sites who gave testimonials look small or low-rent and that one of their testimonials is from anonymous.