Article misses the target: As landline use shrinks, phone polls become a tough cell

The recent article, "As landline use shrinks, phone polls become a tough cell", fails to mention the "VOIP factor," or voice-over-i-p phone usage across the United States. This includes services such as ATT CallVantage, Vonage, Packet 8 and Skype. I think they will find that the "lower income" demographic is canceled out a bit because VOIP users also tend to have a cell phone as well. Additionally, VOIP phones tend to have more of a traditional form-factor that is not present with cell phones, which are primarily portable and not attached to a home phone system. VOIP phone usually use existing phone systems inside a household, so the only difference is where the signal is coming from.