Notification of actions such as your posts and comments will be sent to a friend. Quickly when you want to be known by people your own behavior and to know quickly the behavior of the other party to the contrary, it is effective to make friends.
When it comes to friends, you'll be able to also exchange private messages. In order to make the project or group site, you can talk about planning in the message with friends, usage is various.
Also, when you want to spread your article in Twitter, you can also ask your friends.
If you have more friends, the road to become celebrity will be short.