Although the service is still in a beta version and although you need an invitation to participate, several German sites have started using it and actually got visible amounts of money, despite the limited user base Flattr has of today.
Here some examples:
- Spreeblick - 110,92 € in 14 days
- Lawblog - 33,06 € in May
- taz - 143,55 € in 12 days
- Yucca Tree - 17,54 € in 15 days
- Pixelscheucher - 0,52 € for 5 clicks
- Robert Basic - 4,91 € for 29 clicks
It's not yet big money, but all those who cry saying that you can't earn money with open and free online content could soon be proven wrong...
PS: One question this service raises is whether this is money you have to pay taxes on (the answer is rather a Yes). It also may make a blog become a commercial interest site, preventing us from using content that is put under a non-commercial Creative Commons license.