They basically put ads on your photo's and you get paid per click, with a portion going to charity.
The comapny is owned by Izea who pay for blog reviews, they are known to pay out on time and in full
You have to apply, you can't just sign up - some celebs were using it in beta phase and are raving about it, all looks legit

I might get my daughter to sign up for this one and see how she gets on - she has thousands of pictures LOL