“If I told you that two authors sold a total of a million copies of their books, the most likely combination is 993,000 copies sold for one and 7,000 for the other. This is far more likely than that the books each sold 500,000 copies.”
source: The Black Swan: the impact of the highly improbable by Nassim Nicholas Taleb
The quote is from a discussion of averaging. Few books sell well, let alone in the seven figures (or the six or even the five). The bestselling authors are easy to see and easy to name. Their great shadows hide the many thousands who’ve written perfectly decent books who struggle to get a book published and out to their relative handful of fans. The bestseller is a Black Swan. By looking at the mass of evidence it could not be predicted. We know the occasional outlandish success will appear because we have seen it before. But predictors, Taleb asserts, are usually wrong about where that success will come.