I have moved numerous clients over from comcast to Ooma so we can get a modem in there. (even with CXI its like pulling teeth to get a phone only modem) Most clients just have it for a land line for older folks to call them. When I tell them they only have to pay the taxes ($1.30 -$6) for service they jump all over it.

My parents have had ooma for 5 years now and it just works. Their taxes are $1.09/Month.

the only problem is security systems. There is a way you can get it to work as long the system supports something (i forget the name for it) but most companies are moving people over to cellular anyway!