is this gambling?

i have an idea for a website and i'm not certain, although i think, it is legal. customers register at the site, they do something to earn points. they gamble the points in some sort of raffle, or play games and bet with them. at the end of the month i pay them based on the number of points they have.

important thing to note: they never give me any money, or buy points directly. what they do to earn points does obviously earn me money (as an example, suppose they clicked ads or something).
sites such as pogo.com, operated by gaming giant EA, have similar structures where people earn points from games and enter raffles for real money, but the points are earned purely through playing games (actually, take that back, they do have a subscription service at ~$50/year as well that unlocks more games).

am i in the clear here?

You could do that off-shore perhaps but if you host it in the USA will want to get the permission or at least approval of state gaming authorities.

hmm, but pogo.com is legal? on there you don't get paid for your points but you can enter them into contests for real stuff. of course the points are given to you for free, so that is a difference. on my site tho i'd kinda be giving them to you for free cause you never directly give me any money for them you just do a service for me.
i understand tho it's a sticky situation. i'll try to seek out more opinions.