But when Brandon Sehlke and his wife, Jennifer, moved into a new home in San Antonio two weeks ago, they chose a new Internet phone service from Time Warner Cable, not Vonage or AT&T, his old provider.
The deal Time Warner offered was just too good: phone service with a television package and a broadband connection for a promotional price of $89.95 a month.
"Getting all three services was better than anything else we could find," said Sehlke, a 24-year-old dental student in San Antonio. "I briefly looked into Vonage. But paying $90 for all that was hard to pass up."
As more people make similar choices, Vonage's run as the industry leader is likely to end. While Vonage is still the largest Internet phone company, with 1.6 million subscribers, Time Warner, Cablevision, Cox and others are rapidly catching up, using their marketing heft and their ability to offer bundles of services.
The change comes at an inauspicious time for Vonage and its founder and chairman, Jeffrey Citron. The company isin a that, that outfoxed the traditional phone companies.
Instead, industry analysts are asking whether Vonage can compete--not just against giants like Time Warner, but against even feistier companies like.
"Vonage is not the company people are going to identify with voice-over-Internet phones six months from now," said Jeff Halpern, a telecommunications analyst at Sanford C. Bernstein & Co.
Halpern said that the company "could be getting in under the wire" by going public now. "Vonage is going to be in a position where it is a single-product company, and other companies are offering multiple services," he added.
Brooke Schulz, a Vonage spokeswoman, said she could not comment, citing regulations prohibiting companies from discussing their business before a public offering. People briefed on the company's plans, however, said that Vonage would probably issue new shares on Wednesday.
For now, Vonage remains a success story. It is one of a handful of Internet companies that rose out of the ashes of the telecommunications bubble of the 1990s. While many start-ups ran through millions of dollars and attracted few customers, Vonage took a rather obscure technology and created not only a familiar brand but also a sizable business.
Vonage added 878,000 new subscribers in the last year, including 328,000 in this year's first quarter. Vonage accounted for 29 percent of new subscribers to domestic Internet phone services in 2005; at year's end, it had 31 percent of the market, according to Sanford C. Bernstein estimates.
Customers are moving to Vonage because of its price--$24.99 for unlimited local and long-distance calls in North America and some European countries. The service is so cheap because unlike traditional phone companies that maintain expensive copper networks, Vonage and its competitors turn calls into data and send them over the Internet.
Vonage also offers conveniences like call forwarding, voice mail through a Web site and a portable modem that can be used with any broadband connection, so customers can make "local" calls even if they are overseas.
Vonage has also struck deals with Best Buy, Target, Wal-Mart and RadioShack to sell its equipment and services in their stores, and it is working with an array of manufacturers to develop handsets and other products.
But Vonage's share of the market for Internet calling, also known as, has slipped from 34 percent in 2004 because cable companies are grabbing a greater percentage of new customers. Time Warner had 1.4 million customers at the end of the first quarter, while Cablevision had 900,000 subscribers.
The Internet calling market, which also includes independents like Primus, SunRocket and Packet8, is still just a sliver of the overall phone business. But it is growing at the expense of Bell phone providers like Verizon and AT&T, which have introduced their own Internet phone services to keep customers from defecting. The Bells are also developing television services to win over cable customers.