2005 was a banner year for growth in the US Voice-over-IP (VoIP) market, according to new data from TeleGeography, which found that total subscribers grew 248 percent from 1.3 million in the fourth quarter of 2004 to 4.5 million subscribers at the end of 2005. Even more impressive was operator revenue growth of over 300 percent, from less than $200 million in 2004 to over $1 billion in 2005. TeleGeography projects that by 2010, almost 19 million VoBB lines will be in service, with growth coming largely at the expense of incumbent telephone companies.
Much of this past year's growth has been driven by continued strong performance from market leaders Vonage and Time Warner. Cablevision and recent market entrant Comcast round out the top four operators. Cable companies account for 52 percent of the market, with Enhanced Service Providers (such as Vonage) covering 37 percent of the marketplace. The remainder of the market is served by telecommunications carriers like AT&T and Verizon.