For the past four years, the Interra Project has developed an ingenious model for people to use financial networks to support their local communities and sustainability. Recently, Interra rolled out its first project -- Boston Community Change - in partnership with Boston Main Streets.

Boston residents can get a free (at least for now) Boston Community Change card that they present to participating local merchants. Every time the card is swiped on the merchant’s credit card terminal, portions of the transaction are returned to the user as a cash rebate, donated to a local community based non-profit or school of the user’s choice, and donated to the local Main Streets organization. Merchants sign up for free, and decide how much of a rebate to grant to users.

The Boston Community Change card is not a payment card, and users can pay for their purchase with any payment form accepted by the business. Users receive monthly electronic statements detailing total rebates and donations.

As Paul Ray, author of the “The Cultural Creatives,” has said: "The Interra model is a brilliant social and financial invention that can help bring a green economy into greater practicality. This is hot stuff, and needs all our support. It functions rather like an alternative currency or an airline miles program, to help encourage mutual loyalty among green/socially responsible consumers. In particular, it does a better job of incentivizing a mutual loyalty of businesses and customers who share the same values."

Interra has identified more than 100 cities for possible roll-out over the next 3-5 years.