I am not a big fan of online survey sites because I think answering survey questions is very time consuming in relation to the compensation that you get. Most of the surveys are longer that 20 minutes, and I have even come across a few that take almost an hour.
Another issue I have with survey sites is that sometimes you get halfway through the survey only to find out that you don’t actually qualify for it. Basically, you waste all that time for nothing. Many times I don’t qualify for surveys. I guess I am not the right demographic. It would be nice if they told you from the start that you don’t qualify instead of making you answer half of the questions.