Good question. Its not as difficult since I've taken enough of them by text and IM. Its called regularity. I know how a normal text, IM booking goes. A text/email booking I expect 3 exchanges at the most. If they dont either exchange a number, give an address, or call me after that...Then I know where its headed. (Unless its a long-distance booking)
An IM booking? usually no longer than 5-10 minutes (20 min. the absolute maximum). And anyone who ask for more than the 2 pictures thats on my profile which clearly shows my body and face I decline. I also expect them to exchange numbers and address by the end of the conversation.