Who knew? “Green” stamps are no longer the pre-historic version of “reward points.” Does anyone out there remember licking those endless little stamps and pasting them into that  little book?

No matter. That’s so yesterday. Today the US Postal Service has another kind of “green” stamps, a page of 16 stamps, each with  an idea for reducing your environmental impact. These are “forever” stamps, too, which means they are evergreen as well: You can use them even after the next rate hike.

But, wait, there’s more! The post office is doing more than chanting the old “recycle, share a ride, compost, insulate your home” mantra. It’s setting an example.

The Morgan Processing Center in New York City has the largest green roof in the city and one of the largest in the country: 2.5 acres of grass, benches, an art wall, and native plants. The roof was made by recycling the old roof and will last twice as long as that one did. What’s more, it’s saving the postal service $30,000 a year on HVAC.

In fact, it’s green efforts in 2010 saved the US Postal service more than $27 million. That’s a lot of green: saved water, energy, less going to landfills, and a much smaller carbon footprint. Don’t tell me that social responsibility doesn’t pay!

In fact, the postal service is proud to announce that it “is the first federal agency to publicly report its third-party verified greenhouse gas (GHG) emissions via the Climate Registry.” Its goal is to reduce GHG emission 20 percent by 2020.

The postal service wants you to shrink your footprint, too. You can start by using the free envelopes and boxes you pull out of the racks at your local post office. They are recyclable, manufactured sustainably, and with safe ingredients, an accomplishment certified by MBDC Consulting, which looks at materials used, recycling potential, use of renewable energy, water stewardship, and social responsibility.

I’m delighted that the postal service is socially responsible and helping others do so as well. It’s practical green ideas for small businesses who use direct-mail marketing include:

• Regularly update and improve your mailing lists to limit duplication and waste.
• Use research to effectively target your customers. Folks who live in apartment buildings, for example, probably don’t need lawn services.
• Allow customers to opt out of your mailings to ensure you’re not sending them unwanted mail.
• Use recycled materials for the mailings you create.

Guess what? Those green ideas make sense and  will save you money.

The postal service also provides a link to the Direct Marketing Association’s environmental planning tool, which explains the Triple Bottom Line – people, planet, and profit – and gets you started on a multi-phase plan to minimize both expenses and your carbon footprint.

So hip, hip, hooray for the US Postal Service on Earth Day!

How is your business reducing its carbon footprint this year? Check out the resources suggested by the USPS to see if there’s more you can do.