Wii U / Mario Kart 8 sales idea

There is a recent, albeit doubtful, rumor that Nintendo may be releasing an e-shop demo for Mario Kart 8

If such a demo were released, what if it came with a discounted upgrade to the full version for those who refer a friend to purchase the Mario Kart 8 Wii U bundle (also rumored, but very likely)?

The incentives of getting Mario Kart 8 cheap, along with the desire to play with friends online could promote increased Wii U sales. This could also help increase "buzz" about the game.

Feel free to share thoughts / other ideas, or to simply comment on the likelihood of Nintendo releasing a demo (clearly an unusual move; seems unlikely when considering the companies history.)

Too complicated

Also people would complain that the retail copies were still full price