I agree that FB can be a big time sink. Every time I consider removing FB from my phone, I realize how much I learn about marketing on FB from the ads I see and the groups to which I belong.

If your job involves online marketing, being on Facebook is almost like research for one's job. And without maintaining a connection to this world, it's easy to lose touch with what other marketers are doing and rely on blog articles -- which are, oftentimes, out of date and common knowledge by the time one comes across them organically.