They do exactly what they set out to do. You do usertests and then when you are successful, you get paid two weeks later into your PayPal account. I've had a few problems with some tests in the past but this was mainly because of the tests themselves and/or the creators haven't done a very good job. Usertesting.com have always been fair & reviewed my low score, which ends up them always overturning it, because they feel I didn't deserve to be scored in such a way. Good experience, I just wish I could get accepted to more tests!