Sales figures are the big secret of self-publishing with plenty of estimates but no solid basis for working out how many ebooks are being sold by Amazon and the rest.
There are various scales that have been drawn up and even an online calculator which purports to tell you the range of daily sales for a book in a specific rank on Amazon. Having used some of these tools, I have to say they don’t offer much accuracy and can be way off the mark but that’s not surprising when you consider the obvious vagaries of the Amazon ranking system.
The basis for rankings seems to change constantly and must also be subject to widely varying trends of buying, such as when a new best-selling book emerges which skews the total market figures. There are also some strange anomalies from time to time. For instance, I was looking recently at the sales figures for two of the books I have published. Book A had sold four times as many books as Book B, which itself had sold a reasonable amount. You would think Book A would be well ahead in the rankings but it was, in fact, ranked around 30,000 while Book B, despite fewer sales, was ranked 11,000.
The only truly reliable indicator must be your own sales reports and these are generally kept confidential for obvious reasons as publishers don’t want to give away information to rivals. But Galleycat reports that a new book, Behind The Story, Interviews From 20 Self-Published Authors Who Made It Big by Denise Kim Wy, reveals sales figures from some highly successful writers, including Hugh Howey, whose Wool series has sold over 500,000 ebooks and brought him major print book distribution plus a film deal.
Self-publishing phenomenon Darcie Chan says she has sold around 700,000 copies of The Mill River Recluse while Elisabeth Naughton reports she gave away a staggering half a million copies of Wait For Me in a successful bid to make the book a best seller. Her giveaway tactics certainly seem to have paid off as the book has a colossal 2,250 reviews on www.amazon.com.