Publicize to Facebook
Facebook Share Button
You can add a Facebook Share button (and other sharing options such as Twitter, Google or Pocket) through Settings → Sharing in your dashboard.
To add it to your blog, enable the sharing options you want and drag the Facebook button from Available Services to Enabled Services.
Read more about this on the Sharing support page.
Facebook Like Box
If you have a Facebook Page (not just a profile), you can add a Facebook Like Box to your sidebar or other widget area simply by adding the Facebook Like Box widget from Appearance → Widgets in your blog’s Dashboard.
The page needs to be public and shouldn’t have any age or geographic restrictions if you want it to be visible to everyone, like in this screenshot below:
You can also add, into a post or page, any individual update from a public Facebook timeline. We have a full guide for embedding updates from Facebook.
Commenting with Facebook Accounts
All WordPress.com blogs automatically allow Facebook users to login and comment using their Facebook accounts. Our system makes commenting super easy for your Facebook readers.
Browser privacy extensions and add-ons, such as Facebook Disconnect, may interfere with some of these features and may need to be disabled.