I think most people use their cell phone as their main contact phone number, but because our door bell is hooked up to a land line we need to have one. (lame.) Ryan recently bought the ooma to hook up to our existing phone and I’m really impressed with the service and quality of phone calls. The initial cost for the unit is more expensive than I would have like to have spent, but we won’t have a monthly phone bill ever again. Click here to learn more about it.