Very few people use landline phones for much of anything. So when you talk about things like online chat and social media messages and emails, what you're really talking about is the full extent of human communication.

Recently I have come to assume that any call to my landline is from a telemarketer or an automated call from Terminex letting me know that our regularly scheduled pest-extermination service will occur on its regular schedule. So I usually ignore my home phone.

Not since the steam engine has any invention disrupted business models like the Internet. Whole industries including music distribution yellow-pages directories landline telephones and fax machines have been radically reordered by the digital revolution.