Why do people spend to much time on facebook?

Ahh I often wonder why do people spend so much time on facbeook? at times it's a great place to post and share ideas. Other times not so much. It's a good place to keep up to date on things, and build thinking groups and common goals thing. But other than that, at tims it can bea big waste of time. I do like to talk about what kind of booze I consume on there however.