There are many ways for authors to define success, and for different book marketing campaigns, your goals may vary — for example, you might not expect to generate ROI (return on investment) from a free discount or a new release campaign if your goal is to boost exposure. But if you want to cover the costs of a promotion or make a profit, you may wonder how to measure your ROI effectively. That’s what you’ll learn in this post!
Before diving in, we want to acknowledge that it’s nearly impossible to accurately attribute an exact number of book sales to a particular marketing campaign. It can take repeated exposure to a book for a reader to purchase, and some of that buying journey isn’t easily traceable, given factors like word-of-mouth sales and limited reader data from retailers.
Given this challenge, measuring marketing ROI isn’t about knowing exactly how much money your campaigns are making, but getting a general idea of whether your marketing efforts are working (and paying off!). Data won’t tell you the whole story, but it can help you decide where to keep investing in the future — and where to stop spending your hard-earned marketing dollars.
How to calculate ROI
To calculate the ROI of each promotion or campaign for a book, you need to know four things:
- Campaign cost: How much did you spend on your marketing campaign?
- Books sold: How many books did you sell during the promotional period?
- Book price: How much did the book cost when you ran this campaign?
- Royalty rate: What was your royalty rate? For indie authors, this could be anywhere from 35% to 70% or even higher. For publishers, subtract the total royalty rate, including the cut paid to retailers and authors (if applicable).
Your campaign cost should be readily available, and later in this post we’ll talk about how to estimate your book sales. But when you have these four numbers, you can plug them into the following formula:
ROI = ((book sales x book price x royalty rate) – campaign cost) / campaign cost
This formula can work for any book marketing campaign, including your BookBub promotions or ads! For example, say you’re running a BookBub Ads campaign on a discounted book. During the week the campaign is running, you sell 100 copies of your book at $0.99. If your campaign costs $25 and your royalty rate is 35%, your equation would look like this:
ROI = ((100 x 0.99 x 0.35) – 25) / 25
The first part of the equation represents your revenue ($99 gross revenue multiplied by your 35% royalty rate). Subtracting the cost of the campaign shows you your profit of $9.65. Finally, divide this amount by the cost of your campaign to arrive at your ROI, expressed as a percentage: 39%. Anything above 0% is a positive ROI, meaning you made money on this campaign!
Now let’s imagine you ran another marketing campaign for this book that generated 120 book sales. At first glance, it might look like this campaign was more successful, but what if it cost $50 instead of $25? In this case, your ROI is -17% (((120 x 0.99 x 0.35) – 50) / 50), which means you lost money on the campaign.
To sum up:
- A positive ROI means you made money on your campaign.
- An ROI of 0% means you broke even.
- A negative ROI means you lost money on your campaign.
To achieve a positive ROI, it’s important to control your costs and monitor your results, so that you know which promotions to pull back on and which ones to continue or fuel with more of your marketing budget.
To measure ROI, I keep a spreadsheet of daily ad spend, number of downloads, and royalties earned. I check these numbers daily and adjust my ad spend accordingly.
— Jeana E. Mann, author of Foolish Mistakes
Methods for estimating book sales and promotion ROI
There are several ways to determine whether you sold enough books to make money from a marketing campaign or to evaluate its effectiveness. None of them are perfect, so consider whether the benefits outweigh the drawbacks for your particular marketing plans and goals.
1. Look for a spike in sales
Did you see a spike in sales after starting the promotion? This is the simplest way of thinking about whether a promotion was effective. Self-publishing expert Joanna Penn suggests first taking baseline measurements. “Go into all your sales platforms and note down the baseline sales and ranking prior to the promotion. This will give you a starting point so you can measure the success of the promotion later on.”
After the promotion, you can return to your sales dashboard and check how much of a spike you had for the promoted book and other related books, like books in the same series. This may be enough information to know whether the money and time you invested in the promotion was worth the result.
- Benefit: No math required! All you need is your sales data.
- Drawbacks: Your mileage may vary — even if you do see a clear spike in sales (and it might not be obvious!), you won’t know exactly where those sales are coming from.
For both your promo book and others under your author name, check the rankings and how much of a spike you had, check your email list and any other metrics you decided on. Was the outlay in money and time worth the result? Did the promotion meet your expectations? If not, why not? What can you learn from the experience and what can you do better next time?
— Joanna Penn, author of Successful Self-Publishing
2. Turn off other campaigns
To more accurately connect a jump in book sales to a particular campaign, you can temporarily halt all other promotional activities — whatever sales you have above your daily or weekly baseline can then be attributed to the campaign you’re currently running.
- Benefits: This is the most accurate way to isolate the impact of a single campaign. It can also help you evaluate your paused campaigns — if your sales drop when you pause them, you’ll know those campaigns are making you money.
- Drawbacks: It’s not always feasible or efficient to pause everything. You also risk the opportunity cost of pausing campaigns that might have generated sales.
3. Use link tracking
What if you can’t see sales data for a promotion? For example, in your BookBub Ads dashboard, you can see how much you spent on a campaign, but we don’t have access to sales data as that lives with your retailers. One surefire way to track sales in this case is to use attribution links. Some retailers have services, like Amazon Attribution, that create unique links to track clicks and sales from your ads or other campaigns. (Always be sure to check the terms of service of your advertising platform.)
- Benefit: You’ll know exactly where a sale came from.
- Drawbacks: Even this method isn’t 100% accurate in terms of capturing all sales. Some readers may buy your book some time after seeing your ad through additional word-of-mouth recommendations or from a separate search. Some authors have also experienced delays in reporting — you may need to wait a day or two to see all the data.
4. Leverage a sales tracking tool
If you publish “wide” and sell your books on multiple retailers, tracking your sales across multiple platforms can feel overwhelming! Rather than spend time downloading individual sales reports and crunching the numbers manually, you can use a sales tracking tool like ScribeCount or Book Report to aggregate all your sales for you and present them in easy-to-digest charts.
- Benefits: Sales tracking tools not only save time, but can be helpful for keeping track of all your sales trends and earnings in one place, even if you’re not a wide author. These tools can also provide important insights, like the percentage of sales from different retailers, and any data inconsistencies indicating issues to fix or successes to double down on.
- Drawbacks: Depending on the integrations a tool offers, you may not be able to track revenue from all the channels you use to sell books, including direct sales platforms or libraries. Reporting delays may be a factor here too, as sales trackers rely on the data retailers provide. Also, because these tools aggregate all sales, this method is best for monitoring an overall increase in sales during a campaign period.
5. Consider other metrics
Because even sales tracking and attribution isn’t 100% accurate, you might want to use it in tandem with other campaign metrics like total clicks or click-through rate (CTR). Some authors assume that if a campaign is getting lots of clicks, then by the marketing rule of seven, those clicks will lead to sales somewhere down the line. At the very least, CTR can be a good metric for judging a promotion’s effectiveness relative to other promotions.
- Benefit: It’s a good idea to look at multiple data points to get a full picture of whether a campaign is working well — or if it’s not working well, where readers aren’t converting.
- Drawback: Clicks don’t guarantee sales. This method doesn’t take into account any gaps in your marketing “funnel” where people are clicking, but not buying.
I’m 100% about looking at the numbers to determine whether an advertising strategy is working. I also know that not every impression or click will result in someone buying a book. So, aside from just the sales numbers, the CTR is very important to me. If people are clicking through, I know that my ad creative is effective… and that if nothing else, they’ve noticed the book — so if they didn’t buy it this time, they might buy it next time they see it — whether it’s on social media, an online ad, a print ad, or face-out in a store.
— Alex Nicolajsen, Director of Social Media & Digital Sales at Kensington Publishing
I used both ROI and click-through rate to measure success. For each BookBub Ads campaign, I checked the click-through rate and killed anything under 3%. I also looked at ROI, but it’s REALLY hard to kill an ad when it’s at +5% CTR no matter what the ROI is. I believe those clicks will amount to something at some point.
— CD Reiss, author of One Night with Him
6. Don’t forget sell-through
If you’re promoting a low-priced book to hook readers into a series or other related books, and only accounting for that individual book’s sales when measuring your campaign’s ROI, the margins can look slim! You should include both sales from the promoted book and follow-on sales to get a full picture of total income that can be attributed to a promotion.
You can also calculate sell-through to estimate how much to spend on a promotion or whether it might be worth the investment. With BookBub Ads, for example, you can choose how much to spend on your ads — and if you want to make sure your campaigns are earning more than you spend, we suggest using CPC bidding to keep costs low and calculating a bid that ensures your campaigns will be ROI-positive.
- Benefits: Calculating sell-through is critical for understanding your total return on investment. It can also help identify potential leaks in your funnel — if you can see good sell-through on books one to four but a drop-off on book five, for example, you know there might be friction in your reader’s buying journey, like a broken link to the next book in your back matter.
- Drawbacks: It can be tricky to calculate (though our bidding calculator can help!) and there will likely be a delay as readers work their way through — many authors suggest allowing at least a couple of weeks for readers to buy your next book.
Everyone’s read-through rates are different, so it’s important to calculate yours in order to make an informed decision. If your prices are higher or if your series contains more than one paid book, you’ll see a positive ROI and start earning a significant profit even faster.
— Erica Ridley, author of The Viscount’s Tempting Minx
My ongoing BookBub Ads are predominately for free first-in-series books, emphasizing my longer series so the cost of advertising is spread across more books and my ads more easily reach a positive ROI. I use CPC bidding to keep a firm grip on the cost of clicks. Low-cost clicks are essential to my goal of keeping advertising juice flowing to multiple series.
— Patricia McLinn, author of Sign Off
Tools and resources to help you track sales and ROI
- Sales tracking tools: ScribeCount, Book Report, and The Author Helper are popular options that integrate with major retailers.
- Book distribution services: In addition to helping you publish to multiple retailers, most book distributors also allow you to track your sales across retailers.
- Our Book Marketing ROI Calculator: A ready-made spreadsheet for quickly calculating your ROI. Download the Excel file or copy the Google spreadsheet.
- Our Ads Bidding Calculator: For ad campaigns, this spreadsheet calculates the read-through rate of a series and the overall expected return for each reader who purchases book one. Download the Excel file or copy the Google spreadsheet.
- Online author communities: If you prefer to track your sales manually, don’t be afraid to ask your community for help! Try asking around on social media — many authors are happy to support one another with advice or blank copies of their spreadsheets.
What to do with this data
Once you know your marketing ROI, you’re well-equipped to make smarter marketing decisions. Changing your book’s price, bundling it with more books to increase value, bidding higher or lower on an ad, improving your promotional copy, or nixing any promotions that are too expensive — rest assured you have options! Ultimately, if ROI is important to you, success comes from doing more of what’s ROI positive and less of what’s not.
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