Photo by Michael Grunow

Wall Posts
When asking questions, for which you are expecting a response, write a message. Do not ask the question on the person’s wall.

Comments
Use comments to participate in a conversation about a particular wall post. Do not talk about anything else, for two reasons: First, the person who made the initial post did not intend for it to initiate other topics of conversation, and they may find it difficult to politely redirect the conversation back to the original topic. Second, all of the other people who are participating in this particular conversation about this particular comment will receive a notice about your comment, something they may not be interested in.

If you like a post, click the like button, and if you have something constructive to say about it, leave a comment. Otherwise, the person posting will feel like they are talking to him or herself.

Application Requests
Only send application requests (Mafia Wars, FarmVille, etc.) to all of your friends once. Beyond that, only send the requests to people who actually participate in the application. (Most applications indicate which of your friends use the application.)

Group and Page Invitations
When you are inviting people to your group or page, consider that there is a difference between people who support the topic and people who want to get involved in the topic. Some people will feel obligated to join your group or be a fan of your page just because they like you and/or they support what you are doing. Do not, then, annoy those people with incessant messages that they have to delete from their inbox. If you would like to engage both groups, it may require you to create two different groups, for the different levels of involvement.

Messages to Fans
If you control a fan page, do not bombard your fans with messages. Only use messages to communicate very important information. All other information should be communicated in wall posts.

Friend Requests
Only ask people you know personally to be your friend. If you are receiving too many friend requests from people you don’t know, it might be time to create a fan page. And, if this is the reason you are creating a fan page, nobody will think your creating one is arrogant.

Do not take it personally when people don’t accept your friend request. Some people only use Facebook for their close friends and family. There is nothing wrong with this decision.

Photos
If you post an unflattering photo of your friend on Facebook, do not tag them.

General
All offline ettiquette still applies. If you shouldn’t do it in the real world, don’t do it on Facebook either.