This is just drawing from my personal experience and not a biased opinion whatsoever -- WorldWinner is totally legitimate and it is ENTIRELY POSSIBLE to make a profit off the games. Yes, you CAN lose money...but that's why you can play the games for free and develop a certain level of proficiency before jumping into some cash games.
Is it worth paying into? You can actually play on WorldWinner 100% risk free! When you're comfortable with making a cash deposit, go ahead and make a $20 deposit -- you'll get a $20 game credits bonus, and you can withdraw your original $20 back. You can play solely with the $20 bonus and you'll get your original $20 back within a couple days.
WorldWinner never gives away your personal information without your permission prior, and the most information they'll need from you is some W-2 info if you win enough money to necessitate filling out a tax form.
There are different types of tournament formats....there are 5 player tournaments where the 1st place person wins, there are daily "open" tournaments in your skill level where the top 20 win a cash prize, there are 100 player tournaments where the top 10 win a certain prize, etc. There's usually something to satisfy everyone's fancy.
If I were you, I'd play on the site a little bit more and consider if playing the games for cash is something you'd actually want to do. There's nothing wrong with just playing the games "for fun" without the rewards (or consequences) of playing for money. Let me tell you though...winning money online feels awesome. BLING BLING COLLEGE TUITION PARTIALLY PAID FOR
Jacob, aka Meikyousisui on King.com & Worldwinner.com