Dream2Advance ad from Visa televised on TV Networks is an excellent example of getting people to buy your product by giving incentive to them. The whole program is nicely conceived it is one of my favorite ad going around now along with that of Intel speaking of which "Go Do Something Wonder full".
You can share your Dream on the website and they are trying to get the dream come true. You have to register for an Visa card to get the benefits though
Visit http://dream2advance.com to know more about the campaign