I know you have seen them - the survey to call or go on-line at the bottom of your receipt when you make a purchase. It usually only takes a few minutes to answer the questions about your experience and it can be a great savings. I know that I have seen these at stores and restaurants.
Some surveys put you in a random drawing for a monthly prize like at Target and JCPenney. I honestly haven't won anything when I take the time to answer the survey, but it does help to give them feedback to improve future shopping experiences.
I personally like the surveys that offer you a savings on your next visit. It can be a free appetizer at a restaurant or a dollar savings on your next store purchase. I got a survey on my receipt when I shopped at Bath & Body Works on Black Friday. When I completed it it gave me a code that was good for $10 off a $30 purchase. I combined it with their after Christmas sale and got a great assortment for $20 instead of $30 (that would have been ~$80 if I paid the sticker price!). They will make great items to add to a goodie bag or year-end teacher gift.
Have you gotten any great perks from filling out an exit survey?