Do they sound too good to be true? If so they probably are too good.
For everything in life, if someone is offering to give you money, ask yourself what they are getting in return. Normally it is a skill or similar, or if they are paying just for your time ask how your time will make them money or their life better. For these surveys, who is making money from your involvement and are they making enough to give you at least minimum wage for your time?