Are paid online surveys a scam? well to tell you from my own personal experience most are! but there the odd legitimate programs that will give you the chance to make money but they are very few and far.
The main thing you need to look out for when looking to do this type of work is to make sure that you have read all there terms and conditions, do some background research on the program, and ask around in forums, get opinions of others who have been there ,well done research is research that well benefit you in the long run.
The main concern i have had with these programs in the past is the extra mail you will get from hundreds of companies looking to get your opinion on their product or services , this is all very well for you because the more surveys you get the more money you make. Having a separate email account will stop these companies form overloading your personal email account with spam, you will be thank full that you got a separate account.
The companies that i will consider scams are the one's that merely set up well looking sites full of promises of making you money in minutes and then leave you high and dry, another thing to watch for is that these sites will make it so overwhelming for you to sign on the dotted line they will entice you with a lot of free stuff on top of the offer.... this is what they call in the trade getting allot more for your dollar.
I myself have moved on from doing surveys, in the past i did earn some extra money at the time but for me personally it was time consuming and the company i did surveys for didn't really pay me enough for the amount of time i spent doing them, although it is a good investment if you want extra income on the side , but as for a full time income i would suggest looking else where.
If you do decide on getting paid to take surveys online then as i said before research is the key to finding the right one, don't let the extra products they offer entice you into making a decision that you may regret in the long run. Good research online will determine weather or not they are legitimate, find reviews or forums about the site you are thinking of joining, it will be better for you in the long run to know what your getting yourself into before joining any online survey program.