1) remove you from junk mail lists so that the 702 catalogues you get every month that go directly from your mailbox to your recycling bin will stop coming to your house, and 2) plant one tree per month in your name.
So. Is it a nonprofit or a commercial endeavor?
This is what greendimes says about itself:
"For a dime-a-day, GreenDimes will reduce the marketing at your home, help you maintain your privacy and plant a bunch of trees on your behalf.
GreenDimes is the first service from Tonic, the socially responsible lifestyle company that finds uplifting ways to invigorate and strengthen people's lives and the planet. Tonic is good for you and good for the planet. www.tonicgeneration.com"
Does that make you
a) more interested,
b) less interested,
c) more trusting of them and how they will deal with your personal information,
d) less trusting of them and how they will deal with your personal information, or
e) none of the above
f) all of the above.