NEW YORK (CNN/Money) - Wireless price wars aren't good for companies such as Sprint PCS and Nextel. But the cutthroat environment suits one tech company just fine.

Boston Communications, which manages the prepaid wireless plans for Verizon Wireless, Cingular and several smaller carriers, has seen its stock price increase 46 percent this year.

With a prepaid plan, a cell phone owner can buy a finite amount of minutes up front as opposed to signing a contract with a monthly subscription rate. Carriers are increasingly targeting prepaid plans towards teens and consumers with poor credit in order to boost subscriber growth.

Boston Communications tracks the amount of minutes that customers have left on their plans, sends out messages to alert customers when they need to buy more minutes, and partners with institutions such as ATM operators and Western Union to give prepaid customers a way to buy more minutes.

Sounds kind of boring, but the company's financial results aren't. Last week, Boston Communications reported a 53 percent increase in sales in the first quarter and earnings of 18 cents a share, compared with a loss of 9 cents a share last year.

The company also raised its earnings guidance for the year to a range of 78 to 80 cents a share. The previous range was 52 to 58 cents. Boston Communications earned 34 cents a share a year ago.

But can Boston Communications (BCGI: Research, Estimates) keep growing at such a heady pace? One cause for concern is that Verizon and Cingular are by far the company's two largest customers, accounting for 78 percent of its total revenue in the first quarter.

While having two customers account for such an overwhelming majority of revenue is certainly a risk, there is hope that Boston Communications will continue to add customers as more wireless carriers push prepaid plans.

"The company seems pretty upbeat about the potential to add new customers," said Steven DeLucia, an analyst with Sidoti & Co., a research firm that focuses on small-cap stocks. Boston Communications has a market value of $324 million. DeLucia doesn't own the stock and his firm does not have an investment banking relationship with Boston Communications.

To that end, AT&T Wireless and Sprint PCS have prepaid services of their own and manage the plans in-house. And as these companies continue to look for ways to cut costs in order to juice profits, Boston Communications may become an attractive option.

"Companies are looking at their operations and deciding where they can outsource. It is a trend that we are seeing and Boston Communications is benefiting from that," said Sunil Reddy, manager of the Fifth Third Technology fund, which owns the stock.

Even if the company doesn't add many more customers, Boston Communications stands to benefit as long as existing customers keep pushing prepaid plans, said Tavis McCourt, an analyst with Morgan Keegan.

That's because Boston Communications' contracts with the carriers -- which typically last two years -- are not for fixed dollar amounts. The company makes more money if it helps increase subscriber growth as well as the amount of minutes per user, said McCourt. He doesn't own the stock and Morgan Keegan has not performed investment banking for the company.

And despite its huge gain so far this year, Boston Communications is trading at a reasonable valuation -- 24 times 2003 earnings estimates. "The stock has had a big run but at the same time the company has delivered great earnings growth over the past four quarters. The stock's move is warranted," said Reddy.