US subscribers to Internet-based telephone services grew 21% to 6.9 mln in Q2 2006. VoIP revenues for Q2 2006 were up 173% at $607 mln across the United States, compared with a year-ago level of $221 mln, TeleGeography reports. Cable TV companies now account for 60% of VoIP subscribers, up from 52% in mid-2005. Vonage and other pure-play VoIP providers serve the remaining 40%, or about 2.8 mln subscribers.