After you have done all the work to get a potential customer in the store, the biggest problem is getting them to sign on the dotted line. You may often throw in extras like extended warranties, or cash discounts as a way of getting people to sign. However, those that have offered travel incentives have found these to be a far more effective tool to get someone to sign the purchase agreement, and it often costs them less money.
Why not also use this opportunity to upsell? Set a minimum purchase requirement, so that if the customer buys $2000.00 worth of your product, they will be rewarded with a complimentary cruise or trip for 2 to Las Vegas!