People claim to have earned a lot through survey online on different forums. But I am yet to come across a survey site that pays really good as claimed by others. When I was new to online earnings, I joined many survey sites. But soon I realised that most of them were a waste of time for me. I restricted the time spent on survey sites and devoted more time on forum sites. I come from India and now I am very clear that survey sites and the earnings from them depend a lot on your geographical locations. Most of the survey sites especially the good paying ones are favourable for tier one countries.
I have limited myself to YouGov, Toluna and Rakuten Insight. These three have worked well for me. I have made decent money from them over a period of time. You can check abd see if these sites work for your location.