In December, Amazon US released its 2015 in-house all-format all-category bestseller list. They also published other lists, for bestselling books on Amazon in 2015, regardless of publication year and a separate Kindle list too. Then the newspaper USA Today came out with its own industry-wide all-sources version. What was the difference? Two words: The Martian (good movie, but the book was better). It was number four on USA Today’s list and number four on Amazon’s Kindle list – but it was number 16 on Amazon’s physical book list. There were other titles in the same anomalous situation. Why?

Because, even now, for most books and most people most of the time, the biggest spur to purchase a physical book is seeing that actual book in a physical place. Because for most people most of the time, reading is a take-it-or-yawn-leave-it activity. Books are not quite distress purchases, but neither are they exciting enough for enthusiastic online hunting. (Again, for most people most of the time, which I’ll stop repeating now, but only if the e-fanboys agree to discuss the real world, not their pretend version. Deal?)

So why would a physical book be number four on one list and 16 on another? Nothing sells physical books better than physical displays in bricks-and-mortar locations. Millions of people passed by bookshop windows or airport bookstalls, and saw The Martian, and some vague impression clicked in and they said, “Oh yeah, that’s supposed to be cool”, and they bought a copy, and enjoyed it. Same for the other anomalous titles. That is still how books get sold. Research bears it out. Physical eyeballing is way ahead of any other prompt, be it word of mouth, spam, social media or other kinds of advertising.

Which is a problem for Amazon. Classically it uses books to hook customers and then data-mine them. But it gets only dedicated book buyers. Browsing on Amazon isn’t great as a casual experience: fatigue sets in. (How do you make something totally invisible? Put it on page 17 of an internet search.) And Kindle hasn’t taken over the world. It has settled into a solid niche, like those tiny tubes of toothpaste – essential for travel, but no one uses them at home. (Down, fanboys! Real world!) So there is no way for Amazon to replicate that happy, random encounter with a physical bookstore window. Yes, there are bots and algorithms, but those casual millions of three-books-a-year people never see them: they don’t buy books online.

Which is a defeat for Amazon. It prides itself on going where the customers are, and doing what the customers want. And it needs to. Its growth demands all the customers there are.

So now, rumour has it, Amazon plans to open another 299 physical bookstores (it already has one, in Seattle). The rumours are denied – or at least, not confirmed – and at first glance they appear economically insane. At the best of times, books are low-velocity, low-margin items, and commercial rents are geared to the opposite – clothes, handbags and other high-profit stuff. But then, for 20 years Amazon has proved willing to eat losses, and investors have allowed it to.

So, what if? And suppose those 300 stores were only the start? We’d quickly approach a de facto monopsony. Amazon would become the only practical route to market for 1,400 US publishers and a million US self-publishers, for either digital or paper product. The history is worrying. Amazon has already tried to use its power in a punitive fashion, as if determined to hurt publishers financially. All kinds of fees and “contributions” are required. “Pay to play” was openly the name of the game, until Amazon’s lawyers suggested a less explicit description. One publisher resisted, and a senior Amazon executive boasted: “I did everything I could to screw with their performance.” Already, self-publishers have only “terms and conditions”, which change capriciously – so far only to Amazon’s advantage. Is it good public policy to allow one corporation to have total power over a nation’s published output?

This article was amended on 15 February 2016. An earlier version failed to make clear that the Amazon list on which this article’s argument was based was for books published in 2015 only. The Martian was published in 2014 and was therefore on a different list that measured Amazon’s bestsellers in 2015, regardless of publication year. This has now been included and the text amended to take The Martian’s Amazon sales into account.

Lee Child is a regular Special Guest at the Theakstons Old Peculier Crime Writing Festival; Special Guest tickets are now on sale for the 2016 festival, hosted at the Old Swan Hotel, Harrogate, 21-24 July.