This Ipsos i-Say review and tutorial will give you an inside look and show exactly how it works and who it is for.
One thing you have to consider before you join is the payout methods in your country. In many countries, Ipsos i-Say offers to payout via PayPal but in some countries, you can only get paid in gift cards. So you need to make sure it offers payout methods you are interested in before you start taking surveys there.
Overall, Ipsos i-Say is a decent paid survey site and it is fairly easy to use. And you can also download the Ipsos i-Say app to take surveys on the go.