Here's a new argument for opening your company's books: it's a marketing tool. Unipower, a past Inc. 500 company, has discovered just how advantageous it can be for a private operation to publish its annual report.

The annual report of the $22-million Coral Springs, Fla., electronics manufacturer details sales, number of employees, orders, net income, and balance-sheet information. "But the real meat," says marketing chief Ed Schneider, is a four-page section called "Understanding Unipower" that lists the company's markets, sales channels, competitors, and top 25 customers.

Why go to such lengths? "It tells our customers they're doing business with a real company," explains Schneider. "They can look at the sales history and say, 'My God, they're growing, and they have inventory under control." He adds, "We want to impress customers and intimidate our competition. Everyone is teaming up with a limited number of suppliers. You have to set yourself apart."

Since it published its first annual report, four years ago, the company has grown 933%.

Unipower's annual report has also helped the company squeeze more from its small public-relations budget. In 1994 it garnered numerous business-news mentions, ranging from a couple of lines to full-page stories in trade publications, business journals, and local newspapers. Unipower doesn't retain PR or advertising firms. It can't afford them. Still, the company gets consistent coverage on a shoestring budget; Schneider says he spends about four hours a week on PR.

Unipower's founders are careful to act as if they were managing a public company -- they know how because they used to run one. If you haven't, you should keep in mind one caveat to this strategy: be prepared to back up your claims.