QuickThoughts - Do extra incentive questions give you anything?

I did a survey for $2 which was fine. At the end it told me I qualified for more questions for an extra incentive. I accepted. It did this about 2 more times and costed about 5-10 extra minutes. At the end, I only got the original $2. Does any extra come later from them, or is it pointless to do extra questions? Thanks!