The only problem with those site are you can meet many people that you have something in common with and that may be the case with him, he may have met someone else that was more willing to meet him than you were and he may still be seeing that person now or he may have felt that you were brushing him off and wasn't really interested in him, what you need to do is to write him an email explaining why you couldn't meet him and also tell him how much you enjoyed his conversation and miss it. Ask him if you did anything to offend him and if so could he please explain what that was because you don't understand why you stopped communicating. This may be your only way of getting the answers that you need from him, either that or you just let it go and move on but that won't be easy for you to do because it's not everyday you find someone you click with and have so much in common with so don't let a misunderstanding get in the way of possible happiness.
There could be many reason you haven't heard from him he may have given up on trying to meet anyone now or like I said before he may have found someone else and that is why he hasn't replied to you yet. What I would do is let it go and maybe move on and find someone that is more understanding when you cannot meet them. This is just a waste of time if you have written him several times with no reply.