You can see how AddThis button work if you click on AddThis button in the button right corner on the end of the post.
It is a free widget that shows a number of bookmarking options at the end of a blog post. Readers can bookmark the post on Digg, Technocrati, Google Bookmarks, Favorites and other services with a single click.
The AddThis button spreads your content across the Web by making it easier for your visitors to bookmark and share it with other people.
If you’re interested in adding AddThis button on your site visit : http://www.addthis.com/
Example how work AddThis on digg.com:
- John is a visitor of blog http://interestingwebs.blogspot.com/
- John like post "Improve blog experience with AddThis button"
- If John is already registered on Digg to submit a link he need to :
- enter description
- choose a topic
- prove that he is a human
- Next step John need to check that post is original and that is all
- Now post "Improve blog experience with AddThis button" is posted on Digg.com, this is good
- If Lucy also want to submit link of post "Improve blog experience with AddThis button" on Digg.com she need just to give vote to article beacuse John already submit a link
- Owner of the blog has advantage that his post is on Digg.com and that is the reason why you want to have AddThis on your blog or web
Of course submit of link on Digg.com is just one of options. There are more options like : Technocrati, Google BookMarks, Facebook ...