To free, or not to free? Adventures with KDP Select and game theory

Last weekend I ran a free promotion on my novel. Even more ridiculous than that, I paid  two companies to help me give away even more than I could do myself.

Why would I do that, and what has it got to do with doves? Read on to find out!

“Not to be.”

A quick introduction to game theory.

To help understand why people deliberately undersell their work we can take a glimpse into the wonderful world of game theory, which is a study of cooperation, conflict and decision making .

There’s an exercise in game theory called prisoner’s dilemma, in which two individual criminals are separated and have to decide whether to cooperate or defect. If they both cooperate they get a one-year jail term and if they both defect they get a two-year sentence. If one cooperates but the other defects then the defector goes free and the cooperator gets a three-year sentence. There have been many variations on the game, but the upshot is that the best long-term outcome is for both parties to cooperate, but the safest short-term one is to defect. Prisoner’s dilemma is a fascinating concept, and to pay homage I borrowed the name for an action that a relative of one of my characters takes in my novel.

In a similar vein for evolutionary biology, in the hawk-dove scenario (devised by Maynard Smith and Price) two personality types are competing for the same resources. If two doves meet they will share, if a dove meets a hawk then the hawk will win and get all of it, and if two hawks meet they will fight and risk injury. A real-world example of this is UK motorway road works. We see that ‘1 mile’ marker and, doves that we are, all slowly move to the inside lane and the growing traffic jam. The outside lane is nicely empty and then suddenly some tosser hawk in an Audi (probably) zooms past and cuts in at the very end. The hawk ‘wins’ the battle of the queue and gets home faster. As nice as it sounds in theory, the all-dove system is not stable as a few hawks can take advantage and get to the front quicker. Too many hawks, however, and they all get highly stressed, both lanes get clogged up, most likely compounded by idiots cutting each other up at the last moment. The result? More delays and probably an accident.

So, what has all this got to do with books?


I’m free, to do what I want, any old time.

Gold star if you get the connection

As authors, we are in competition with each other for readers; both their time and their disposable income. I’m quite a slow reader and that, coupled with the fact I have many other interests, means that I can only read a very limited number of books. As a result, I tend to stick to genres I like and until recently, authors I know. I’m sure I’m not alone! Even though there are potentially millions of readers out there, only a fraction may be interested if you write genre fiction and even fewer if you are an undiscovered author.

Coupled with the hundreds of thousands of new books each year in the Kindle store, this makes the pretty much saturated market very difficult for new and unknown indie authors to enter and flourish. You’d think therefore that charging a reasonable amount of money for our works would be sensible thing to do, to maximise what small returns we may get whilst still giving value to the customer. Going back to game theory, if we all cooperated and charged a minimum price of, say, $2.99 or even $3.99 for our books we’d all benefit. But that is an unstable system; it would only take someone to charge $0.99 and they’d have an advantage. So to compete we all start doing it. We all defect because a smaller return on a sale is better than no return at all. It’s actually even worse than no sale, because the reader might like it and recommend it to their friends resulting in a greater loss of potential return for us.

And what’s even cheaper than nearly nothing? Actually nothing! There is a very valid argument that you should never give your work away. Something that’s free can give the impression of having no worth or being disposable. Consumers quickly get used to free, and then suddenly everything has to be that way. It stops other authors from making a living because you can’t out-compete free unless you have a strong existing audience.


What’s the point of giving away content?

There is, however, I think a good argument for running a free promotion for a short amount of time, as can be done with Amazon KDP Select. It helps give authors exposure and gets their books into the hands of many more people then it possibly would otherwise. It’s a short-term promotional tool for a potential long term gain as the word is spread. Nothing is a better advert or incentive than a personal recommendation from someone you know.

The counter argument for this is that just because someone downloaded your book doesn’t mean to say they’ll ever read it. Perhaps they downloaded a hundred free books that day? Perhaps they do that every day! Certainly, the power of magpie’ing is a powerful draw; as a gamer I have quite a lot of titles in my Steam library I bought because they were on sale, and hope to play one day if I ever get around to it. There is so much free stuff out there these days though that consumers have to be discerning to avoid being drowned in it. In my opinion, if they downloaded your book it shows they are at least interested in it.


The experiment – materials and methods

There are two types of experiments in science. There’s the proper hypothesis-driven study, in which everything is tightly designed with proper controls, a minimum of variables changed to allow meaningful analysis to generate robust conclusions.

Then there’s the ‘quick and dirty’ experiment which most scientists will admit to having done at various times during their career (I know I have!). The experimental design is typically a case of ‘hey I have a cool idea! Hmm, wonder if this’ll work if I just do this…’ and is run without much proper control. If the initial result yields anything exciting, then the plan is always to repeat them with everything controlled properly (which can occasionally backfire spectacularly depending who you told about the initial result). My experiment in giving my novel away was definitely the latter of the two.

The king of free book promotions is probably BookBub, but they only tend to take more established titles and are pretty expensive. Plus they turned me down when I applied. So instead I tried Books Butterfly who guarantee at least 1,100 downloads through their various networks (although only if you use them exclusively, which I didn’t). I also used Book Marketing Tools, who don’t have their own network but supply a form script to make applying to multiple sites and blogs easier. I didn’t check, however, that all of the sites actually ran my book, and at least two I got mail shots from didn’t. On the plus side, it’s pretty cheap and possibly worth it if you’re busy or lazy.

This was, therefore, not a controlled experiment comparing different companies against each other, but rather a test of if anything works at all. At this point I’d like to say a huge thanks to everyone at the Digital Fix Forums, who have been very supportive in showing an interest in my work when they didn’t need to, and giving valuable feedback and telling me that my book didn’t suck. One of the members also very kindly put my promotion on HotUKDeals. On top of this I ran my own tracking through a link on my Twitter and the Digital Fix Forums bargain thread, and my current BooksGoSocial promotion added the #free tag to their postings.


My promotion ran Friday to Sunday, and here are my results!

download graphs

In total, I got 1,587 book downloads. I’m probably hearing lots of groans of ‘pah I sell that many in an hour!’. Well, good for you! I don’t – this isn’t an attempt to show off, but just the data as reported from my KDP page. As a baseline, before the promotion started I had a few thousand KU pages and very few sales in the month or so that my book had been out.

Kindle free charts

For for the free books charts, my novel reached #3 in Science fiction, #2 in dystopia and #2 in post-apocalyptic.


For for the free books charts, it reached #17 in Science fiction, #12 Dystopia and #11 post-apocalyptic.

In the UK Kindle store overall, In Vitro Lottery reached #40 (I was out at the time and couldn’t get a screenshot unfortunately). If there’s anything to take away from this whole event, it’s the satisfaction that for one brief moment in time more people were downloading my novel than they were War and Peace 🙂

In your face, Tolstoy!


My book reached 272 degrees (I have no idea how they measure this – either by upvotes, click-throughs or both) and made the ‘hottest this week’ list

HotUKdeals 272


For my own link I got 52 click-throughs.



My numbers are very modest compared to many others I’m sure, but from a baseline of pretty much zero I don’t think they’re bad at all. One thing to note is that my downloads in the UK were much better than for the US. This could be due to the larger number of reviews on the UK site, the HotUKDeals effect, the fact that it’s set in Britain, or a combination of all three.

So, has my promotion catapulted me to J K Rowling levels of sales, or had Ridley Scott on the phone demanding the film rights? Well no, and I didn’t expect it to (although it would have been nice!). I did, however, see a spike in sales the day after the promotion had ended and hopefully some KU downloads as well.

I seriously doubt I would have gotten that many downloads without an active promotion behind the offer at this stage in my career, so even though it cost me money I think it was definitely worth doing. It’s a gamble of a payoff later on for sure,  but what investment or advertising isn’t? The next experiment will possibly be a negative control; to run a free promotion for a couple more days in the future and not tell anyone.

My experiment does highlight the point that even with relatively low numbers (hundreds rather than thousands, in the UK at least) it’s possible to get pretty high up even in the more generalised Kindle charts.

Would I do it again? Most likely yes, but probably not for a while. I’ll keep applying for BookBub every month in the vain hope I’ll get picked up…



Made it to the end? Thanks for reading! Please find some links below if you are interested in learning more about game theory.

More about game theory

More about Prisoner’s Dilemma

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