facebook is a breeding ground for disappointment. It's not real life and people get all too attached to thinking it is. I would stick to calling or texting and if you consistently get no reply I wouldn't bother with those people anymore why should you go out on a limb none stop only to get met with silence? Third time around of no response it's obviously not just a "I'm too busy" I'm sorry but no one is literally that busy that they can't respond to a FRIEND within a week or two!