HELP! Probability That Any Book May Be Read

I have a question and I'm hoping people can impart some wisdom to my dilemma. My dilemma is lack of data to apply to this problem. The question I'm trying to answer is the probability that any book (in the English language) may be read by any Joe Bloggs.

The reason I want to know is because of the protagonist in a new novel thats being written, who is a writer, is on the brink of publishing his book and wants to ascertain his possible readership. This is what has been written:

"Jay grappled to calculate his possible readership—based on a universe of 2 billion English learners, according to Wikipedia. A prominent American research institute cites, eighty-five percent of these “English learners” don’t actually buy books in any given year, approximating to a market-size of 300 million people, which coincidentally, correlates roughly with the number of active customer accounts on If every one of these people bought the mean number of books, which Pew says is fifteen, from the range of books ever published in human history (129 million books according to Google), each publication would be bought at least thirty-four times, giving him a readership of at least the same amount. And considering that of that number of books consumed in any given year, only forty-three percent will be read to completion—effectively, this means that his book would be read in full by only seventeen other people in the entire universe."

Is Jay's thinking correct? Is there a better way to think about solving this problem? I think it yields inaccurate results because it is calculated using average. I'm thinking somewhere in there we need the probability of something (e.g. non-fiction books consumed or fiction book consumed, etc). Could we say it with a reasonable degree of certainty?

I'd appreciate discussion to solve this very perplexing problem.
Thank you


TS Contributor
He devides the total number of books expected to be bought bei English-speaking customers next year by the total number of books ever written in history, in any language. I'd guess that this particular mean value is therefore a bit dubious.

But using mean values as expected values is not a wrong approach here, especially if humour is involved. One could think of using additional information in order to achieve more accurate estimations, e.g. how many books of the same genre as written by this author are bought in a typical year, and by how many customers.

Just my 2pence