Online survey scam
An Online survey scam is a site that says they offer money or gift vouchers to participants for answering questions. Usually, these sites ask the user to spend an unreasonable amount of time, for insufficient payout. Often, the promised money or vouchers are never payed out. The main goal of an online survey scam is to obtain demographic information that the site may sell this information to spammers or other marketers.
Other scam survey sites may charge a fee for accessing a list of survey sites, which a well-informed participant would be able to find for free by using search engines. Theses fee sites may also charge to refer a participant to a different site with the same survey.
Note: Even if a survey site is legitimate, the payout is too small to generate any substantial income or make it worth your time.