USA Today talks about “the newest form of literary self-promotion”—Twitter. Certain authors tweet for self-promotion (Philippa Gregory is tweeting this week in the voice of a character from her new novel), while others use it to complain about bad reviews (Alice Hoffman). Aravind Adiga, the Booker Prize winning author of The White Tiger, uses Twitter to connect with his readers so he can avoid book tours. There’s a lot that can be done in just 140 characters, and authors are trying it all.
Literary License is on Twitter ("literarylicense") but isn't particularly active.