My Email #1: Emailed guy on ok cupid because he sounded smart (one of few) and he mentioned xkcd in his profile, so I mentioned a couple of my favorite strips.
His Email #1: He drops the name of a niche computer program that I use often, which is actually extremely weird. Why would he think I would know what that was? And writes 4 or 5 more paragraphs, mentioning that he is away for 6 months and including no questions. Maybe he is clueless and doesn't realize he isn't giving me a way to continue the conversation.
My Email 2: Wow, I use that program a lot and ask why he uses it because I'd thought he was a computer programmer from his profile. And ask a few questions to keep the conversation
His Email 2: No, he's in my small sub/field. And 1000's of miles away. This email is like 2 sentences long also with no questions.
My Email 3: See you at the annual conference!
Another case: Also ok cupid. I email a guy in the fall, again one of the smart ones. he turns out to have been at my graduate school when I was and I was almost certain that we knew some of the same people. He CLOSES his profile. (I know he didn't just block me because I have a second account and tried from that one as well.) Did he just enter witness protection?