One of the reasons health clubs stay in business is by signing up people to yearly contracts.
What they know and the general public doesn't know is that a great majority of people who do sign up only attend about 57 days out of the full year while some drop out completely, thus affording more space in the gym for more people to sign up and fail to show.
It seems that Wii Fit, at least in Japan, is taking on similar characteristics in consumer behavior. According to ITMeida of Japan, a poll was taken by a group of 1000 gamers that showed a staggering amount of people not using the Wii Fit game shortly after purchase.