Tuesday, August 25, 2009
The EREC data is based on books that are on sale, or were on sale during the last 365days. Thus as books drop from the set, earn more, and enter the set--the mean sales figure changes. These changes across time are shown on the "tracker"graphs.
The figure below relates to the average number of copies sold by a book that has been on sale for one year or more. Notice anything interesting? (You can click on the figure to enlarge it).
And yes, many of those lines don't go all the way to the end. I need a minimum of five books by three different authors to report a publisher-specific figure. And it seems like authors from some presses have stopped reporting?