At PrevaLeaf e are currently consumer testing five natural products in the feminine health space.
Survey monkey has been perfect for us.
Simple to create a survey for each product and then we ask approximately ten questions per product.
It is also easy to set up and easy to modify.
Their model is freemium. If you want to see it in operation check out 'feedback survey' on www.prevaleaf.com
The problem we found was in the conversion i,e, getting people to take the time to go online and fill out the survey. Many people told us the products worked fabulously and were really happy to have them but making the effort to go online......well we had to figure that out.
Starbucks cards as rewards did not work. We found the solution rapidly by having (paying) a nurse to call each person 15 days after they had received the sample.
I hope that helps