As am employer, marketing professional, or parent, keep in mind that rewards should not be overly complicated. If you make them too complicated, they will not inspire or motivate which was likely your intent from the beginning.
Not sure you agree?
Do you choose a grocery store where you are required to use a card to get a discount and then do you use a gas station where you have to use your grocery card to get reduced price gas? Maybe you do and maybe you don't...but in reality, it's complicated for most people. I need to find my coupons, remember what day is double coupon day, find my grocery list, make sure I have my card...then I need to make sure I have enough points on my card to warrant driving out of my way to the gas station that accepts the card and I need to make sure that I'm making that drive on a day that I need gas and prior to the points expiring. If I choose not to use the points for gas, then I can redeem them for a particular item on a particular day or something to that extent.
Really? I'll be honest with you...I usually drive across town to the discount store that doesn't take coupons, doesn't have a store card, offers no gimmicks or incentives, and simply provides me with quality service, products, and price. We are all very busy and simple goes quite far.
Keep rewards simple and more people will be interested in them. Make them too complicated and you'll defeat the purpose.