I think having free ebooks available to readers is important. I had three free ebooks out for nearly two years: a short story, a novella, and a novel. I did it because I assumed no one would even consider buying a book from an unknown, self-pubbed writer.
Anyway, people might not have bought the books, but they did read them and review them. I was stunned. Now, I've put a price tag on the novel and it is selling, not in large numbers, but at a rate that surprises me.