I have always believed that the best marketing concepts involve humor. Commercials that use humor to sell their product seem to be much more widely distributed. These types of commercials tend to reach far beyond their original target markets. This is largely due to the internet. People tend to pass these videos around like wildfire.
A great example of this is the Trunk Monkey series of commercials used by Suburban Auto Group. The commercials promote a local car dealership, but they have been more widely viewed online than they ever where in their small local targeted area.
Another great example of this type of promotion is the recent short film released from Covad. The film uses suspense, and in turn humor, to publicize its products in the Voice Over IP market. The promotion is interesting and intended to get peoples attention. And, this type of promotion should have a more lasting effect as the link to the site is passed around over time.
These types of promotions are perfect for the internet. People enjoy them and they tell their friends. In time, the promotion only stands to gather a wider customer base because it will last longer than the marketing campaign that created it.
Check out both of these sites. They are both a lot of fun.