Here is a really nice idea for the charity banners. Developed by Garbergs agency to help the homeless of Stockholm check the Homeless Banners.
How it works?
The idea is simple, yet memorable and to the point. The agency produced a set of banners to suit different sizes and pushed them out to the Internet. 36 various websites “adopted” these banners free of charge throughout the campaign and while the banners were visible in these websites, they were showing how long each website was adopting them and therefore, supporting the campaign. These banners were also developing warm colour the more clicks they receive.
Check out the campaign video here: