About a year ago I read that only 20 % of the people who download your book for free will ever read it. (badredheadmedia.com)
You can download these books for free if you'd like first crack at them. (jaxonreed.com)
However, a certain percentage of the people who have downloaded the book for free actually read the book, liked it, and decided to pick up the next books in the series. (sarracannon.com)