Vindale is an online survey site that requires you to pay for a service (often a monthly recurring fee) and then evaluate the service. Your first month or trial period for the service being evaluated is paid for along with a few dollars for your time. Make sure you cancel your trial membership that you had to join or you will face these recurring charges.
Vindale has a generally bad reputation noted by many users and forums discussing surveys. I wouldn't recommend them to anyone. If you are looking for something free to do, you can try legitimate paid surveys that have already been outlined on the site and don't require you pay anything to get rewarded.
Why should you have to pay to give your opinion?