So here's how this whole thing works…
In order to get paid for taking surveys online, you need to register with websites that offer this sort of thing (…duh). These survey websites that you register with are paid by brands to get your input on all sorts of things - from your TV-watching habits, your favorite places to eat, what material of sweater you prefer in the fall, etc.
So, in order to get you to take these surveys, survey sites will offer you money, gift cards, and all sorts of other cool stuff in return. Since they are being paid by the brands themselves, they are basically passing off some of their compensation to you. Think of the survey websites as the middle-man between you and the companies/brands that are doing market research.
With that being said, some of the surveys are fairly targeted. For instance, Bed Bath Beyond doesn't really care what kind of candles a 23 year old guy in a punk rock band prefers so they aren't going to pay to get his opinion. So what does that mean for you?
You won't be eligible to take every survey. When you register with a survey site, they will collect some basic demographic info on you and match you up with surveys that fit your profile. Since no one survey site is partnered with every brand doing research, that means…