This is exactly the type of application I wish I would have been working on!
To market Just dance 3, a game for Wii, CP+B created an iphone app that makes everyone a great dancer! Just record a video of your friend, baby or animal dancing. They don’t even have to dance great. The app will synch their movement to the music and in a minute you have your own perfectly synched dance video with music to share with your friends online!
The reason why this is so great is because the users happily create and share content online highly relevant to the product and target group! An app that makes everyone a good dancer should encourage even the worst dancer to buy a dance game!
Thanks to @Gotsche