I have an experience that found a girl in Facebook who work around my office, of course I found out by chatting with her. I started to date her for a drink after work, she keep on reject me. I think she may not feel comfortable to meet me up after work, so I try to ask her for lunch. Know what, she said yes. The different between lunch and dinner? I think she can have an excuse to run after finish the meal as the time period for lunch is much shorter than dinner. This may give you some idea when you want to make your move next time. My own experience, patient is an important point.
Frankly speaking, it's more easier to know someone face to face. Facebook maybe a way for you to know some new friends only you are so desperate and you never hang out. If you ever have a chance to hang out with your friend, why don't you start from there? As we have mention above, it's easier for you to know someone when they have a drink or two, they are in a relaxing mood. You may get to know them in just an hour, if you are lucky, you may have an explosive sex after that. No more long hour waiting for her to online, and cut so much time and problem. Good luck for your hunting.
