Coined by John Zeratsky in a series of blogposts starting here at http://johnzeratsky.com/archives/001380.php
"We’re at the dawn (mid-morning, actually) of a new age (The Subscription Age?) in which all the content we care about — news, opinion, music, movies, television, photos, contact info, events — will become subscribable.
Much of it already has.
What’s more, I think the technologies enabling this change will become so ingrained in our tools and our lives that we’ll forget the time when we had to check CNN.com every day; or remember to turn the TV on at 8 p.m.; or open an email full of pictures from our family; or send a mass email to friends when we get a new cell phone number.
Instead, the news will be waiting for us. Our favorite show will be recorded for us. Pictures of our families will be automatically added to our albums. Our friends’ address books will always be up-to-date."
"I’m going to talk about three kinds of subscribing:
1. Content delivery. This is the traditional subscription model. We are interested in something, so we subscribe to it. Then, content is delivered to us on a regular interval.
2. Synchronization. This is subscribing to stay current. Imagine event calendars, address books and media libraries that are always up-to-date.
3. Personal subscriptions. This is subscribing to a person. Right now we have our friends’ IMs in one place, emails in another, blog posts in another, pictures in another, events in another, etc. (Yes, it’s like #2, but more about staying in touch than staying current.)