Activity Feed
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I would only recommend this plugin if you believe there is enough activity going on at your blog other wise it wont leave a good impression at the visitors.
Comments
Comments plugin lets users to comment on your blog. A great feature of this social plugin is that when ever someone comments on your blog and leaves the "Post to Facebook" check box ticked, the comment appears on his Facebook activity feed with a link back to your blog and thus making increasing more links towards your blog.
Also this comment box is extremely user friendly and is quite simple to understand.
Facepile
The Facepile plugin shows the profile pictures of all the people who have liked your blog or have signed up for it. You just need to enter your blog URL and your plugin would be ready to go. This again helps only if your blog have enough likes and followers.
Like Box
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Like Button
Like button works somewhat like the "like box" but have a different purpose to serve. Its a more handy button and can be added to places like post headers and footers. Its just allows to like your respective post or your blog as a whole. Today, Facebook likes have become one of the determinants of your online success. Its a must to have plugin.
Live Stream
Live stream plugin lets users to share comments and activity in real time on your blog. Live Stream works best when you are running a real-time event, like live streaming video for concerts, speeches, or web chats.
Login Button
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Recommendation
This plugin features all the recommendations your blog has earned. Whether a particular post or the blog as a whole, the plugin would show that content as recommended by so and so.
Send Button
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Which one to choose?
Facebook social plugins are really one of the best out there as part of social tools available online. Its not necessary that you should use all of them to get online success. Instead work out your needs and then choose which ones you want. The most famous are Facebook like button / box, comments.
We would like to know which of these social plugins you use on your blog.
Thanks