Jeff Edelman, founder of start-up catalog house SoHo Design, in Dobbs Ferry, N.Y., quickly found he couldn't grow by renting mailing lists alone. So he searched for less costly and more effective ways to introduce teenagers to his collection of artsy T-shirts and hats.

That led Edelman to the world of "alternative media," defined as non-mailing-list promotions, such as package inserts. A magazine "ride-along" program piqued his interest: a mailing broker told Edelman of a private mail-delivery service that could couple his catalog in a polybag with, for example, Seventeen magazine.

The drawback: the ride-along program extends to only a tiny fraction of Seventeen's readership. The advantage: "It's a great way to test the market," says Edelman. And it's cheaper than using the U.S. Postal Service. His mailing cost per 1,000 catalogs: $60 using private delivery versus $200 via the U.S. mail. Heartened by the response to his small mailing to Seventeen readers in several major cities, Edelman has planned a bigger mailing, of 50,000, using private postal delivery.

Each time the post office hikes its rates, private mail grabs headlines. It refers to the home or business delivery of certain kinds of second- and third-class mail. Alternate Postal Delivery (616-235-2828), in Grand Rapids, Mich., arranges ride-along programs with magazines such as Seventeen, Redbook, and Popular Mechanics in 55 markets nationwide. Publishers Express (404-429-4500), in Atlanta, offers a similar service.

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