Dunkin Donuts Offers Free Coffee to Blood Donors: What's the Catch?

(CBS) If old-fashioned altruism doesn't get you to donate blood, maybe free coffee will.

At least that's the idea behind the fourth annual "Give a Pint, Get a Pound" campaign put together by Dunkin Donuts and the American Red Cross.

Throughout the month of January - National Blood Donor Month - the campaign entitles blood donors to a coupon that can be redeemed for a pound of coffee at a Dunkin Donuts restaurant.

What's the catch? The campaign is in effect in only seven states: Massachusetts, New Hampshire, Vermont, Connecticut, Maine, Rhode Island, and New York.

Live elsewhere? You're outta luck.

The goal of the campaign isn't to warm up New Englanders during the chilly winter season. It's to help ensure a steady stream of blood at a time when the red stuff is often in short supply.

"With the holidays and the weather, typically over the winter months we see a shortage of blood," Red Cross spokesperson Donna M. Morrissey told CBS News. She said the Northeastern U.S. needs about 3,000 units (pints) of blood each day just to meets its basic needs.

Blood has a shelf life of 42 days, according to Morrissey. And each unit donated may help save three lives.

If you're a java junkie, you may be disappointed to learn that people can give blood only once every 56 days - which means you're limited to only a single coupon during the month-long campaign.

But there is a workaround, says Morrissey: You can donate platelets (the clotting substance) once every two weeks - which means you can get two coupons good for two pounds of joe.

Sounds like a bloody good deal.

For more information, or to find out where you can donate blood, call the Red Cross at 800-GIVE-LIFE or point your web brower to redcrossblood.org.