John Tropea takes a pass at explaining how sharing works on Google+ (Google Plus):
How is it different to Facebook and Twitter?
As an online relationship model; Facebook is symmetric, Twitter is asymmetric, and Google Plus is asymmetric
- Follow (asymmetric) – enables you to follow people (those people don’t have to follow you back in order for you to see their content in your stream…you are basically their fan)
- Public – your posts are shared in the public
- Friend (symmetric) – you cannot read and send each other updates unless you both follow each other (this is called “friend”)
- Private – you posts are not shared in the public, instead they are shared with all your friends only (this is called a “walled garden”)
- Selective Reading & Sharing – you can also read and share with just a selection of people (this is called “Lists"…this isn’t a primary design feature and isn’t used that much as far as sharing goes)
- Follow (asymmetric) – enables you to follow people, just like Twitter, where those people don’t have to follow you back
- Public and/or Private – your posts can be shared in the Public, or just shared with All Circles or a selection of Circles
- Selective Reading – you can also read posts in a stream from just a selection of people you follow (this is called "Circles”)
- Selective Sharing – you can also share posts with just a selection of people (this is called “Circles”)…BUT unlike Facebook, unless “those people you follow in your circle” follow you back, they won’t see your post in their stream, instead they will see it in an alternative stream called “Incoming”.
Posting to Circles
I post about my trip to Melbourne and limit this to my Family circle (this circle has 6 people in it)
Because I’m so used to Facebook I have assumed that all those 6 people will see my post.
Wrong? Only the 4 people that have followed me back will see that post in their “Stream”.
The other 2 people will only see that post if they look at their “Incoming” stream.
The 101 – when you choose a Circle only the people that follow you back will see your post
Posting to Public
It simply means that all people that follow me will see my post in their stream
Just say Judy follows me, but I don’t follow her (therefore I don’t have her in a circle)
And just say I post to a Circle, and not Public.
This means Judy will not see my post at all.
Posting to Individuals (Mentions)
This has nothing to do with Circles.
But just like Circles and Public; Individuals are a selection you can make in choosing an audience to post to.
The way you can post to Individuals is pre-fixing their name with an “@” or a “+”
The difference in limiting to who sees your post using this selection is that it will also send that person a notification that you have “mentioned” them. Which kind of makes it very similar to the Twitter @mention feature. In Google Plus there is a stream called Notifications where you can view all these pushed mention posts.
Google+ requires me to create a mental model: the intersection of actions that I have taken, such as following others or putting them into circles, and the actions they have taken, most importantly whether they have followed me or not.
One snag in this is that there isn’t a simple way to know who exactly will see what you post in Circles when you do so. Another snag is that your stream is defined by the union of all those you have Circled, which is another thing that is not easy to find out.
A confession: I am not currently using Google+ actively. I am sitting out the surge of interest because I actually don’t have a burning need to use it, and the social dynamics remind me of Friendfeed, with the same people advocating it.