What are the differences in the rewards: cash, prize or sweepstake?
Cash rewards are given out to participants of paid surveys through check, PayPal or bank transfer. The cash reward is listed for each survey and the participants know it before attempting the survey. Prizes are given out in the form of cash or gifts. Each participant who has successfully completed a survey is entered into a pool and winners are chosen. Some sites clearly display the percentage or odds of winning. Sweepstakes are held as draws with an assigned frequency of occurrence, commonly having cash prizes. These are held for all panelists and participation in a study is not a criterion for entry.
