Each of the E-Lab studies has an assigned probability of winning and the prize listed on the front page of the website. The probability and the chances of winning are varied by the length of the study. The odds typically vary from 1/20 to 1/50 and the prizes vary from $10-50 in the form of an Amazon gift certificate. If you are registering from outside the U.S., please check Amazon.com’s shipping rates, policies, and availability to your location. We take no responsibility for their inability to serve your location. You will see the information on probability of winning and prize before you start any of our studies.