Romance authors seem to do chats all the time, talking up the upcoming chats on their online groups. I don't think I've been to very many mystery chats, but we could give it a try. We'd need to post on Dorothy L and the yahoo mystery groups to tell people what authors will be chatting and the time and place should get us some people. You can post an excerpt of your book (not too long) and tell the story behind writing it.
What do you think? Anyone interested?