Facebook is one of the most popular social networking sites in the world. With its continuously growing number of registered users, it is quite likely that visitors who come to your site will already have a Facebook account. In this case, it is much more convenient for them to use their Facebook logon details than to go through yet another registration on your site. That's why you should consider using Facebook Connect authentication.
For Facebook Connect to work on your site, you need to register the site, all you need to do is take the following two steps:
2. Set up Kentico CMS for Facebook Connect authentication - learn here
3. Use one of the Facebook Connect web parts on any page of your site - info here
The following diagram shows how the process of Facebook Connect login works: