We all know the number of homes with a residential landline is shrinking, due to a variety of factors. Despite this, having one number to reach the household is still present for more than half of the households in the USA, as of 2014.

With Voice Over IP, or VoIP, service, the Internet is used to carry the phone connection to the outside world. Typically, a small box called an ATA (Analog Telephony Adapter) attach the existing home phone to the Internet via ethernet cable, and instead of paying multiple phone companies for access to analog lines, the Internet is the carrier.
Due to the nature of Voice over IP, your customer does not have to be in your market. You can expand your selling footprint beyond your traditional borders. Furthermore, if you already provide Internet services, or cable services, or both, adding residential phone completes the triple play that major communications companies offer.
What else comes with VoIP? Since the phone is now an Internet enabled service, a whole host of new features becomes available, depending on the provider and package involved.
Voicemail (and Voicemail to Email)
Throw aside your old answering machine, because VoIP service provides voicemail at almost every iteration. In addition to recording messages you can retrieve remotely, you can also have the voicemail recording delivered to you via email. So, anywhere you can get email you can get your voicemail.
Caller ID
A staple of Internet telephony service, Caller ID is still a premium feature for some landline services.
Long Distance Calling
Since the access point to the phone networks is based on the cloud, all domestic numbers are the same distance from you, so long distance calls are usually free and unlimited.
Call Forwarding
Leaving the house for awhile? Simply forward the calls to your cellular phone while you are gone and never miss a call.
Simultaneous Ring
Imagine the home number is dialed, and you, your spouse, and your two teenage children all know it is ringing — even if you are not at home? Now, imagine that any of you can pick up that call on your respective cellular phone just as if you were at the house? Simultaneous ring facilitates this function, and offers the call to up to five devices at the same time.
Smartphone Application
Some services offer an app for a smartphone that will allow you to dial as if you were at the home phone number, eliminating the consequence of revealing your cellular number when you make a call from it.
Administration Portal
Any Internet connection can be used to access a portal where you can set features of your service, such as call forwarding, distinctive ringers and even call rejection without touching your phone or ATA. You can set these features remotely and instantly from anywhere you can access the Internet.
VoIP Residential Service can be a great way to add another product to your catalog, to offer more bundled service to your existing customers, and to attract new ones outside of your footprint. And with the features that wireless telephone customers are accustomed to, you can bring back the home phone to your market.