Facebook’s five new social plugins are aimed at helping websites to increase virality and engagement through Facebook services.
1. The Like Button
The Like Button is the simplest social plugin. No login is required, and it will run in an iframe. Even if you’ve never visited CNN before, you’ll get social context when you visit the site. Now, when users show up to sites that use it, you can see which of your friends like the site, or have engaged with it recently, without the site knowing anything about you. And when users like anything, it automatically gets added to the list of things they like on their profile. The Like Button creates a viral distribution method for content.