Global Test Market is a decent standard of what you're getting yourself involved in. Their practices are not any more or less shady or reputable than almost any online venue – survey or otherwise. Just like Facebook, when you identify yourself accurately with Global Test Market, you can expect them to use that information in any way possible to make a penny. The great news is they inform you and ask for consent first.
The concept of data mining and profiting off that data mining isn't anything new. And while some companies engage in some rather disreputable practices to do this, Global Test Market seems to be doing just fine with the whole “consent to disclose” thing. More importantly, in some cases this may help you as some companies will offer to do more specialized product testing once they've identified you as their target demographic.
You won't get rich doing these things but it's legitimate and you'll get paid in the end. For example, you get a penny for each email you click. You get a penny for a video stream. You can earn dollars for fulfilling offers but those aren't nearly as quick as reading an email. They are upfront in what you get paid so you can decide if it's worth it.
IOCS is a not-for-profit research organization that conducts studies and experiments on shopping-related behavior – things like how we, as consumers, evaluate products, how we make the buying decisions, etc. Although the focus is mostly on shopping related behavior, some of their experiments and studies include broader areas of marketing, psychology, and economics.