If you shoot them a tweet, they’ll typically rep
Post# of 82672
Anyway, if you follow them, they’ll follow you back and they’ll answer questions if they can.
I don’t know it for a fact BUT I believe that most responses to tweets are from Mark.
Sure there’s always email, but that’s more if you have a long question or several questions right? If it’s super quick and just a typical query and you use Twitter whoever it is, they respond quickly enough.