For me, I think there comes a point before the meeting, where it becomes clear that there is a commitment and then it is necessary to belong to only one. Of course, living in the US, a trip to Russia or Ukraine is not as simple an endeavor as for someone in Germany or England, etc. So I need to know that there is a serious potential before the meeting. I cannot commit the time and expense to fly back and forth to Europe every time I meet someone I might like. So, the communication is very important in creating a relationship, with all available tools: e-mail, Skype, telephone, postal mail, cards, gifts, etc. A long distance relationship is real if the two people involved want it to be and are committed to each other. Of course at that point the plans for a meeting are well underway if not already completed once.
As for communicating with other, I think once a commitment is made between the two, there should be then the only ones communicating seriously, of course.