What is RTR and why is it so important?
Read-through-rate is the key to success when it comes to the quintessential method of making money via self-publishing. So if yours isn’t nailed down tighter than a Kansas cowshed, you're in trouble.
Note: I wrote this article in 2022 after the publication of Quiet Wolf, book 5 in the DI Jamie Johansson series.
RTR stands for read-through-rate, and put simply, is the percentage of people who, after reading a book in your series, will then go on to buy your next one.
It can be really tricky to track buyer to buyer, but over time, you can look at average earnings on each book, and work out your read-through-rates. These figures are imperative for discovering where your break-even points comes, and are the only reason that a 300% ACOS might be a viable marketing strategy for your series.
So, a decent book 1 in the series will get maybe a 50% RTR to book 2. Which means that (numbers incoming), if your book 1 is priced at £1.99, you’ll make £1.34 from that sale. If book 2 is priced at £2.99, you’ll make £2.06 from that sale (or similar).
So at 50% RTR, for every two sales of book 1 you make, receiving £2.68, you’ll make £2.06 from book 2 from organic RTR. This means that you can conceivably spend £4.72 to sell two copies of book one, or on average, £2.36 per sale … at £1.99, this is a 119% ACOS.
With three books out, and a 100% RTR from books 2–3 (realistic RTR is maybe 85–95%), you can expect to see:
3 book series: 2*(1.34)+2*(2.06) = 6.84 per 2 books = £3.42 per book = 171% ACOS
4 book series: 2*(1.34)+3*(2.06) = 8.90 per 2 books = £4.45 per book = 223% ACOS
5 book series: 2*(1.34)+4*(2.06) = 10.96 per 2 books = £5.48 per book = 275% ACOS
You get the idea. This doesn’t account for KU royalties, organic sales via Amazon’s own marketing, reader recommendations and spontaneous buys, buys made through VPNs, incognito windows, on fresh browser sessions, etc, etc.
But it does assume you’ve got a killer RTR from book 2–3. This is the one that’s often overlooked, as it has a significant knock-on effect through the series.
Let’s use my figures, and my, quite frankly, sub-par book 2–3 RTR, which is sitting at 66% for the last 30 days. This is 20% below where I’d like it to be. So only 3/5 readers who read book 2 go to read book 3. I want this at 4/5. So let’s look at my 5 book series, and how these numbers are getting compounded, first as raw sales numbers, then as royalties. These numbers are just for illustrative purposes ( I don’t sell this many books):
Monthly Sales
Angel Maker: 1,000 @ £1.39 royalty per sale (RPS)
Rising Tide: 620 (62% RTR) @ £2.04 RPS
Old Blood: 409 (66% RTR) @ £2.04 RPS
Death Chorus: 389 (95% RTR) @ £2.04 RPS
Quiet Wolf: 370 (95% RTR) @ £2.04 RPS
= (1000*1.39)+(620*2.04)+(409*2.04)+(389*2.04)+(370*2.04)= £5037.52
That seems pretty good, right?
Well, let’s look at what happens when we increase Rising Tide’s RTR from 66% to 76%, just a 10% increase.
Monthly Sales
Angel Maker: 1,000 @ £1.39 royalty per sale (RPS)
Rising Tide: 620 (62% RTR) @ £2.04 RPS
Old Blood: 471 (76% RTR) @ £2.04 RPS
Death Chorus: 447(95% RTR) @ £2.04 RPS
Quiet Wolf: 425 (95% RTR) @ £2.04 RPS
= (1000*1.39)+(620*2.04)+(471*2.04)+(447*2.04)+(425*2.04)= £5394.52
Now, of course, it may only seem like £360, which isn’t a small amount of money. But we’re talking about 1 in 10 people feeding down the chain. And if you take those raw sales numbers and scale them, and add extra books to the series, take into account this also affects KU borrows, etc, etc, then this is not an insignificant change.
And it also affects the ACOS you’ll need to hit, too, which we’ll calculate in a bit. For now, this is how much you’ll make from selling ten copies of book 1 with a 66% book 2–3 RTR, and a 95% RTR from 3 onwards …
= (((2.04)+(10*(1.34) + 6*(2.04))*0.66)*0.95) = 18*0.95 = 17.10
Final royalties from 10 sales of book 1 with a 66% 2–3 RTR = £77.66
And if we got that to say, 85%, where we’d want it?
Trust me here, the number is: 47.434 + 22.64 + 21.51 = £91.58 from 10 book 1 sales with a 60% 1–2 RTR, and an 85% 2–3 RTR, and 95% 3+ RTR.
Want the ACOS out of that?
66% 2–3 RTR: 390.45% ACOS on book 1 sales
85% 2–3 RTR: 459.80% ACOS on book 1 sales
Maths. Fun, eh?
So, what does this tell us? RTR is important. No. Freaking. Poopy. You can see here at a 20% RTR increase from books 2 to 3 results in an ACOS break-even increase of 70%, which is pretty massive on raw Amazon Ad conversion sales without even considering KU read royalties.
This is why I set the release of my next book a month later than normal, and have spent the last month tightening up the MS of book 2 to try to get one more reader in every five to buy the next in the series.
I hope that these figures aren’t too opaque. I know they confused me when I came back to them a few days after the initial calculations. And while it’s good to bear in mind they’re only indicative, and that ACOS is calculated off list price, not royalty price, it’s all a bit … murky.
But there is truth to this in the sense that nailing your RTR rates and understanding the compounding effect that RTR has is an important part of working towards a solid income stream from self-published novels.
Hopefully, you found this interesting! Let me know down below what you think and if you have any further thoughts on this.