A recently released survey by market research firm Telephia ranked Vonage and Skype as the most popular residential VoIP calling services. Vonage, continues to dominate the market for home VoIP calling, with 1.8 million households signed up for service, representing 47.5% of the 3.9 million U.S. residential VoIP subscribers. Skype's 463,000 subscribed households was second on the list followed by AT&T CallVantage (218,000 subscribers) and Verizon VoiceWing (196,000), among others.

A significant limitation of the study, however, was that it did not include households subscribed to VoIP calling service through their cable company. With cable television and Internet providers increasingly entering the VoIP marketplace, this is a significant omission. According to a June 2005 study by Telephia, most VoIP consumers feel that their VoIP service quality is on par or better than their wireline phone service. Telephia data shows that 67 percent of VoIP early adopter households felt that the voice quality they experienced with the service was equal to traditional landline service, while 19 percent noted that the voice quality was better than wired phone lines. While VoIP usage has certainly been growing fast, the 3.9 million lines of service still represents only 3.6% of 107.1 million U.S. households with wireline telephone service.

Source: Telecommunications Research and Action Center.  trac.org