I have cashed in some earnings with PCH surveys. Amazon gift certificates (PCH doesn't pay cash), which is what I wanted, were not available. How can you run out of electronic gift certificates?
Watch out. Not all of the survey offers they send you earn points--even some of the ones that take 30 minutes or more. In addition, I took a survey that was supposed to have awarded 300 points. I followed all of the instructions and the survey showed up as completed on my account, but the points were never awarded. PCH claims it was a technical glitch and that I never really completed the survey.
I think I'll stick with Global Opinion or Survey Savvy.