Those are quite analogous to Facebook, no? No. They would analogous to Facebook only if you are a professional web social marketer or something like that. Then

Those are quite analogous to Facebook, no? No. They would analogous to Facebook only if you are a professional web social marketer or something like that. Then Facebook would be to you like github is for programmers. Still 90% crap, but still somewhat professionally useful crap. For everyone else Facebook is 100% unprofessional. (It may not strictly be a waste of time if you consider genuine keeping in touch with physically remote loved ones.)