Google+ provides two ways to share other people’s content. Which one to choose depends on what your want to emphasize: the original post or your commentary on the original post.
1. The Share Link: RT Plus
Sometimes you want to share another post, but you don’t have too much to say about it. You might add a note, a little commentary, or tag it so people know why you’re sharing it with them.
If you are coming to Google+ from the Twitterverse, think of Share as RT (re-tweet). I even use the Share link to clip and save posts for myself. I’ve created an empty circle called Bookmarks. When I share a post to my Bookmarks circle, I add topic-related tags to help me remember what I thought was interesting about it when I go back later to read it.
2. Embedding a Link to the Post: Hat Tips and Shout Outs
Other times a post has inspired you to respond at length. What you want to do in this case is write your own post and attach a link to the original post.
How To: The permalink of each post is in the timestamp. Hover over the timestamp, and copy the permalink. In your post, use the link icon to add it. (Hint: After you paste the link, be sure to actually press “Add”.)
If you are coming to Google+ from the blogosphere, this method is just like including a link in your post in order to reference an article elsewhere or to give a shout out to another blogger.
The important thing is that Google+ has both situations covered. So you can choose whatever is most appropriate for your situation. And you’re not locked into doing it one way every time.
For Sharing Original Content: Focus on Content Providers
If you Share (RT), your readers can share the original article easily. The Share link on your post Shares the original article, not yours. This is Google+’s way of focusing the attention on the content provider, not the linker.
When you use the Share link, you (and your readers who subsequently Share) are sharing just the original article — not the comments associated with either post. This behavior is great when you’re sharing something funny from a celebrity like Felicia Day because you don’t want to spam everyone’s stream with the hundreds of comment she gets on posts.
On the other hand, if you want your readers to share your article (not the original article), use the second method and link to the post. In this case, the original article was just the inspiration and you are the content provider.
For Sharing Original Comments: Discussion Groups
In some posts, the comments are an important part of the discussion. If someone poses a question, then you want to see the answers. In this case, use the second method and link to the post. Before sharing, turn off comments on your own post. This will encourage people to click through on the link you’ve provided and comment on the original post.