Let it be known that the guy that messaged me said he has had terrible luck with the girls on the site so far. Yet, mid conversation when I asked him what was his name... he stopped replying. Yet, the green light is still on, on his okcupid profile.
Maybe you're boring? I mean, I've started many conversations with many girls, and I stopped replying mid conversation when I realized how boring they are. If they can't hold a conversation, I'm out. Then there are many girls who never ask anything about you, which shows lack of interest, so why would I keep talking to her when she doesn't show signs of wanting to know me?
If that's not it, maybe he just got into a better conversation with another girl, or simply lost interest for you.
Well depending on elapsed time, something might have just come up. The point where you start revealing personal information is also an out for some people as that is when it starts feeling, well, personal. Concept of risk etc pops into play.
If he thinks you're better than the other girls he has talked to so far, give him a poke. I bet he still wants to poke you. No need to worry.