This was a hot topic at the convention. I won't say I learned anything earth-shatteringly new, but it was nice to see it laid out simply.
Selling books takes 3 things:
1) distribution -- the books have to be available widely so that people can find them
2) convertibility -- people have to be able to buy the books easily once they find them
3) discoverability -- they have to know the book exists so they can go looking for it
And of course, it is #3 that is the real challenge. The first two items can be handled by hard work and a little technical know how. But getting people to talk about your book, now that is a challenge.
There isn't a magic formula or even someone you can pay to make that happen. Yes, traditionally published novels have a slight advantage in that they are able to get reviewed by all of the big-name reviewers. But even small indie published books can stir up some discussion.
Of course, it is easier to drum up a cry for your book if you can create some controversy surrounding it.
There IS one shocking scene in Sisterhood that I've received some flack over. It involves a psychic sexual assault. What do you think? Is that enough to cause a ruckus?