I'll usually answer, and I try to give interesting or relatively witty responses, but typically they end up not saying anything at some point and I just forget about it. One thing I find is that with some of the apparently dry texters just adding some random thing about your day into the "how are you?" response can sometimes be what it takes to spark more conversation.
(To be fair I don't get too many really dry texters, more often I get completely random people asking if my username would happen to be a KotLC reference lol)
How do you deal with dry texters?
I just chill with it, because Teri's worth dealing with.