Drive the streets of retiree-rich communities in Florida and you'll see a thrift store every few miles — if not blocks. Step inside and you'll spot crowds of shoppers that could make a department store envious.

But it's not just the bargain prices for gently worn clothing or almost-new furniture that attract customers. They've come to socialize, take classes and volunteer in what is becoming a new kind of American community center.

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Thrift stores draw locals who want to volunteer or chat as well as shop. — Photo by Jennifer Silverberg

Typical is a Goodwill store in Sarasota that offers free classes every week in English, computer skills and crafts. Volunteer knitters make blankets and booties for expectant mothers, shawls for people in nursing homes and scarves for the troops in Afghanistan.

"I supply the soda and they bring cakes, pies and other goodies," says crafts instructor Fred Radmore, 65, a retired pilot. "It's a regular party."

Retirees and thrift stores have had a long love affair — but in recent years the relationship has turned red-hot. While many big retail chains have been shutting locations since 2008, new "resale" stores have been booming, increasing 7 percent a year, according to the National Association of Resale Professionals. Today there are about 30,000 coast to coast.

Hard times have brought in hordes of new "thrifters" — one in six adults now shops at the stores. Many are 50-plus. It's more than frugality that makes thrifts appealing, says Michael Gold, who runs TheThriftShopper.com, a searchable listing of more than 10,000 thrifts that benefit charities. "Some customers grew up in the Depression. And many grew up during World War II, with an ingrained understanding of the importance of volunteering."

Many thrifts rely on volunteers. At the Elephant's Trunk, a 13,000- square-foot store in Venice, Fla., they outnumber paid staff 24 to 1. "We've donated $7.8 million to the community since 1951," says store manager Stephanie Elliott. Beneficiaries include hospital patients and their families, students pursuing nursing or medical careers, and the Lions Club.

At the Hillcrest Thrift Shop in Kansas City, Mo., the ties with the older community are strong. The store's weekly 55+ Day, with its half-off prices, attracts busloads. "We sell high-end donations for dirt-cheap, so people can buy items for a dime or a quarter and, I believe, reminisce about their childhood," says manager Lou Warner.

Next: Popularity of thrift stores among retirees is driving changes in the industry. >>