There didn't used to be much of a difference between making information available and notifying people. You can't tell your friend you're free on saturday without taking some of their time and attention, and pragmatics would probably imply that you'd like them to propose doing something together then. It would sometimes be nice to know someone's rough availability before talking to them, but it was all awkward: perhaps you could have put your calendar on your front door? With the internet, however, I can put up my calendar for anyone to check on my front door [2], and if someone finds it useful, that's great. It's up there, like a lot of other things, in case it's useful (and so I can link to it) but not with an expectation people will have seen it.

(In april danner commented that he doesn't "really care what people find out about, as long as it is not broadcasted to people who don't want to hear it." I think this captures the publicy/notification distinction well.)

When facebook added the newsfeed, quite early on, it moved from a place of simple publicy to a combined publicy and notification system. Users were quite upset, joining groups and groups in protest. People had been ok with the idea that anyone from their college could come and look up their relationship status, but they were not ok with their recent breakup being broadcast for all their friends to comment. [3] People's expectations changed, however, and now a facebook without a newsfeed doesn't sound so useful: how would I find out about people's posts?

Google plus' circles combine publicy and notification. I would like all of my posts to be public, but sometimes I write something about contra. There's not a way for me to tell it I want full publicy, but only to show up in the feed of people in my contra dance circle [4]. Not everything is interesting to everyone, and I'd like to not be spamming people.

(I also think that publicy is spread widely in the future, so you might want to practice it now.)

[1] There are a few people already using it but the seventh result is a typo for "publicly". All very casual use, aware of its novelty status. One person, however, has been promoting it since defining it opaquely in 2004 as "the response from public institutions a private person is able to elicit" in an unrelated final paper for a University of Amsterdam Masters degree. The wikipedia page is minimal and I've nominated it for deletion. I hope the word catches on, but it clearly hasn't yet.

[2] Yes, I now have my own domain and am off university hosting. It is very exciting. Farewell sccs; you were good to me.

[3] Their close friends and their socially aware ones might know commenting wouldn't be helpful, but this just meant the comments that did appear were especially useless.

[4] Which google plus limits to 100 people, not understanding that you meet a lot of people dancing.