I recently worked with a journalist, Renee Giroux, author on the blog Stimulating Conversation, who was doing research on book/author marketing and promotion. She collaborated with me and a bunch of other self-published and published authors to gather some important information for everyone to reference. The research she did is part of a 10 week long series, so be sure to check it out at: http://stimulating-conversation.com/blog/2009/08/25/mondays-marketing-your-masterpiece-why-book-marketing-and-promotion-so-difficult/
It's great work, so be sure to check it out!