Some companies will often want you to take a short "screener" survey when you first register with them. Unfortunately these are not usually paid surveys. You'll usually be entered into a drawing, but the purpose of the screener survey is much more important than that ...
The real purpose behind screener surveys is that it's how some of the better market research companies get to know you. It's how they determine which surveys you're eligible for, and it's the "secret" to getting invited to take the really good surveys in the future!
The funny thing is that because screener surveys don't pay cash, many people don't do them - so the odds of winning the prize being offered are a lot higher than you might think.
In short, do not be discouraged if you receive some screener surveys in the beginning - it's really just their way of weeding out those that aren't serious. More importantly, it's your chance to show that you ARE serious - and deserving of the really good paid surveys.