About 8.5 million more U.S. households will start using VoIP for their home phone service over the next two years, according to a new forecast from Pike & Fischer's Broadband Advisory Services.

The number of VoIP-connected households in the United States will approach 30 million by the end of the decade, generating more than $11 billion in revenue for cable operators, telephone companies and network-independent providers such as Skype, P&F predicts.

The Silver Spring, Md.-based market research group reports these projections in a new report, "Residential VoIP Market Outlook." P&F reached its conclusions by examining recent growth trends in consumer adoption of VoIP services, and factoring in the growing prevalence of digital service bundles that include multichannel video, high-speed Internet and home phone. VoIP-connected households are expected to grow at about 14 percent annually over the next five years, P&F projects.

Although top telephone companies such as Verizon and AT&T will see their overall residential lines continue to decline, they will see their VoIP customers increase steadily as they attract more customers to their fiber-optic service packages (Verizon's FiOS and AT&T's U-verse), according to the analysis. The cable industry, which is much further along in capturing VoIP customers, will see subscriber growth slow somewhat from its torrid pace, the report states.

It is unlikely that the smaller VoIP service providers such as Vonage will see much growth because, unlike the facilities-based providers, they lack the advantage of wrapping their service into discount bundles.