Figure 11

Predicting sales. Distribution of the parameters (A) fitness λ, (B) immediacy μ and (C) decay rate σ for all bestsellers, with fiction shown in green and nonfiction in blue. The dashed lines indicate the λ, μ and σ values of The Appeal, indicating high fitness resulting in a higher total sales, average immediacy indicating typical peak sales time and slightly lower than typical decay rate meaning a relatively slow drop in sales after the peak. Predicted vs measured total sales calculated from Eq. (6), using the first (D) 25 and (E) 50 weeks to obtain λ. The colors represent the peak sale number for each book. The first 6 months offers an accurate picture for the full total sales and the prediction accuracy increases as longer times are used to calculate the fit. Additionally, total sales of books with higher peak sales are predicted better than of those with lower peaks