As TerraPass blogger Adam Stein explains, Terrapass sticker buyers are a green bunch. They are five times more likely than the average American to ride public transportation to their job and 22 times more likely to bike to work. Even though the entire idea behind TerraPass is to offset the CO2 from the vehicle you slap the sticker onto, people in the TerraPass community are seven times more likely than average to drive a hybrid. Also, TerraPassers are 200 times more likely to have solar panel installed on their homes.
It does make a lot of sense that people who pay for a little sticker are also willing to do something more for the environment, so I'm not exactly surprised. Still, all in all, this is a pretty good scorecard for TerraPass and the community they've created.