1) You don't consider the day truly started until you've taken the time to read through your friends' page (whilst making your lunch, etc., of course);
2) You have purchased a piece of clothing or other memorabilia sporting its trendy logo;
3) You are seriously contemplating whether or not you can afford to spend time with your family in lieu of sitting in front of the monitor, uploading 32 more userpics for your Permanent Account, because it is just that important, damn it.
citizenjess, here, post is f-locked, QWP
Personally, I'm guilty of #1.