"They are affluent," says Joel Sowers, executive vice president of Centex Destination Properties, which has done its own demographic tracking as it blueprints new housing divisions that cater primarily to the second-home market. According to his stats, their average income is more than $125,000, nearly $50,000 higher than the NAR's estimate. And a lot of his company's buyers are paying cash.

But don't let the statistical averages blur your market vision, says Sowers. "If you go back to the '60s and '70s, families had to decide if they wanted to purchase a second car," he says. "Today, that's happening with real estate. It's not just the super wealthy. We're selling to a much wider demographic than most people would think. And it's not just Boomers," he says, pointing to a long lineup that includes a hefty chunk of 30-something Gen-Xers.

There are two big reasons why people snap up a second home: pleasure and business. More often than not, say the experts, it's a mix of both.

"Most people buy for recreation, but they want it to make sense from an investment standpoint," says David Hehman, president of EscapeHomes.com and a partner in the NAR second-home survey.

The fun part is fairly easy to qualify. People want to have someplace to go to unwind. That could mean a place near a golf course or a ski slope, up in the mountains, or on a beach or lakefront property. People are often inspired to buy their second home in those places where they enjoyed a vacation; that weekend trip to Utah or the week along the Maine shore has inspired scores of people to put down a second stake. Las Vegas, the vacation capital of America, is a big second-address destination, as much for its sunny links as The Strip.

The investment angle on buying a second home, though, takes some studying. And there are some bottom-line results playing in the second-home market's favor.