hI j1gsaw
I am pretty new to this site, but I can say there is no catch!
I came across this site and was a bit sceptical also but signed up and went to poker stars and got my $50 deposit with them. I have to say it was all v easy.
I told a couple of my friends one enrolled with party poker but to receive the $50 he had to make a deposit of about $25 and had to provide details ie. drivers licence and I trhink a utility bill. The other went somewhere else not sure which and I believe is now enrolled also.
I get $10 each for initial enrollment and increments as they start earning strat points.
The important thing is that the material on this site is the best I have come across to improve your game and I am currently playing at NL25 and am making anywhere from 10/100 to 30/100 return on my poker so far. So it is important to understand the principals before you start using your BR. It takes a while to put it into practice but once you know what you are doing you will see your BR increase!
PokerStrategy.com get a rake from your playing at their affiliate sites and we get better rewards as well so a win/win.
Hope this answers your question but also read their bus model
http://www.pokerstrategy.com/businessmodel/ which makes sense to me.
PS I don't know where you're from but if you live in the states I don't think you are eligible to join, not sure why