BookBub Advertising - Does it Work?Does BookBub advertising for self-published books really work?

Todd Gilbert of Who Knows Publishing emailed me awhile ago asking some very good questions about my last book promotion in 2013. I’ve run a few tests, using BookBub advertising, and doing promotions without BookBub advertising at all, and I asked if I could share the questions here, answering them as I go: 

  1. How many days was your book offered for free on Amazon?
  2. How many digital downloads were there for your book?
  3. Did giving away your book spike the paid sales later?
  4. Did the free giveaway dramatically increase reviews?
  5. Did you think doing the free giveaway was beneficial to you?
  6. Would you recommend it to other authors?

If you’re an author, this is good information — cold, hard facts, backed by data. With everything marketing-related, don’t just take my word for it though: do your own research, run your own BookBub advertising campaign(s), and gather your own stats. Every book is different, and every promo has differing variables that will change the outcome. 

If you’re looking for a quick takeaway, scroll down to the section below the questions called The Bottom Line, where I lay the answers to these questions in plain English:

Does BookBub advertising work? Are “free promos” dead? Is KDP Select a waste of time?

The book we’re talking about today is my first novel, The Golden Crystal, an action/adventure (Men’s Adventure is what Amazon calls it) thriller that’s around 100,000 words long. It’s your typical James Rollins/Dan Brownian-esque novel, with plenty of fighting, weapons, and sci-fi elements.

I wanted to test the validity of KDP Select (Amazon’s flagship self-publishing platform and promotional tools) for offering a “free download” of the book. In the past, I’ve offered books (all nonfiction) for free for up to 5 days at a time (KDP only allows 5 free days in any 90-day period), and have been generally underwhelmed with the results.

Test #1: Short Nonfiction – Free Periods Using KDP Select

From my 5 nonfiction promos, each testing multiple promo periods and different 5-day spreads (1 day at a time, over the course of 90 days, 5 days all at once, 3 days free and 2 days free, two weeks apart, etc.) and different days of the week (weekends, weekdays, T-Sa, etc.): 

  • Avg. Reviews Before Promo: 20-30 per book (cultivated using mailing lists, review websites, free preview copies, etc.)
  • Avg. Downloads (Range): 30-50 per book
  • Marketing (Additional mktg. done before and during promotion): Submission to ebook listing websites (most of these promos were before the Amazon crackdown on ebook affiliate linking policies), mentions to mailing lists, social media
  • Avg. Sales Spike (Next 5 Days): 5-10 sales
  • Avg. Reviews Earned (Best Guess — it’s difficult to track post-promo reviews): 2-3

Not much to shake a stick at, huh?

Again, these numbers aren’t anything near what I was hoping for. There are probably plenty of things that could have helped the outcome: 

  • More reviews before promo
  • Mentioning book listings to more websites
  • Better “review request” pages at the end of the books (links to the Amazon’s book page asking for a review)
  • Guest posting before the promos began
  • Paid advertising (driving traffic to the listings, BookBub advertising, advertising, etc.)
  • Trying it with fiction rather than nonfiction

What I wanted to test was the validity of the claims put up by big-numbers site and The BookBub advertising page claims to be the #1 site for paid ebook listings, and I wanted to see what the hype was all about. 

I was also interested in generating some extra holiday sales for my book, The Golden Crystal. I’ve heard it said that fiction generally sells better than nonfiction, but I wanted to test this myself. 

So how did it go? 

Test #2: Novel-length Fiction – Free Periods Using KDP Select AND Paid BookBub Advertising

I tested The Golden Crystal at the end of October, using a 3-day period from Oct. 29 to Oct. 31 for the book to be free. I submitted my listing information for BookBub advertising for a daily email to be sent out to the Action/Adventure list on the morning of Oct. 29. 

This setup allowed me to see two things: 

  • The difference between the avg. daily downloads/purchases before the BookBub advertising and after. Before, I was generating 2-3 sales/day of the book, listed at $4.99 on Amazon for the Kindle edition.
  • The power (or lack thereof) of a multi-hundred-thousand-subscriber mailing list to generate real sales (not just a ton of free downloads)

The listing cost for the BookBub advertising was $110, now up to around $120 as of this writing, and would be for one email sent to the list. 


  • # of Reviews Before Promo: 39 (cultivated using mailing lists, review websites, free preview copies, etc.)
  • # of Downloads (Range): 67 (sales since July 1 release of book)
  • Marketing (Additional mktg. done before and during promotion): none (I wanted a clean sample pool, using only BookBub advertising)
  • Total # of downloads of free book: 35,689
  • Total # of sales (Next 5 Days): 124 (Net: ~$433
  • Total Reviews (Next 5 Days) (Best Guess — it’s difficult to track post-promo reviews): 26

For a self-published author of one fiction book, these are pretty exciting numbers. 

The BookBub advertising clearly more than paid for itself, to the tune of over 300% ROI in the marketing costs. The reviews gained and extended reach through the listing have pushed the book to 78 reviews (most are 4 stars!) as of today. 

BookBub Advertising - Worked for Me!

And the #3 Bestseller in the Kindle Store on Amazon was a nice addition, as well! (The picture shows The Golden Crystal at #4, because it was fluctuating between the two for a few days): 

Overall, I marked the BookBub advertising/KDP promo down as a huge success. The book continued to sell very well through the Christmas and New Year season, finally slowing down to a miserable 2-3/day sales drip around 1/05/2014. Still, I am extremely excited to know that there’s the closest thing we have to a “sure thing” in paid promotional ads through reputable sites like BookBub advertising.

The Bottom Line:

1. Are “free promos” dead? Is KDP Select a waste of time? Does BookBub advertising work?

To the first question, Absolutely not. If “dead” means they don’t work at all, that is. If “dead” means they’re not going to cut it, alone anyway, to generate enough sales to run a full- or even part-time writing and self-publishing business, then yes. 

With my experience, running a free promo on KDP Select, and even using their new promotion, Kindle Countdown Deals, won’t be enough. Here’s the scoop:

To see real, lasting results, you need to plan a major (paid) campaign at least every six months. The BookBub advertising rules require you to wait that long anyway, so plan your first promo to run seasonally during a time when your genre traditionally gets the most sales (or the least amount of sales, if you’re a contrarian marketer interested in pushing your book to more successful, on average, in slower periods of the year!)

For me, that’s just before Christmas through just after, to catch the early-winter sales rush for fiction and the post-Christmas fill-up-the-new-e-reader sales rush. Plan a KDP Select promo, or change your listing at other stores (via Smashwords) to be free for a few days, then push traffic to the listing through paid advertisements through things like BookBub advertising. 

Running these sorts of tests is hugely valuable to the writer trying to make it on their own. And even if you’re traditionally-published, it’s probably worth it to understand exactly what type of marketing you’re getting from your publishing company (hint: probably not much!). 

If you don’t think you can afford this type of testing, you owe it to yourself to try it at least once, using a safe and proven method: save some money for a few months, run a free promo, and drive traffic to the using a niche sub-list on BookBub advertising (Action/Adventure is way cheaper on BookBub advertising than the Thriller category), and test the results. 

There’s a good chance you’ll do better than just break even — and that’s free money! Use the gained exposure, increased sales, and boost in reviews to arbitrage your own way to a bestselling book!

What do you think? 

Have you had experience with this type of promotion? Have you used BookBub advertising?  I’d love to hear your results, and overall experience. Leave a comment below, and if you have more questions, ask them! If I have particular experience that I can share, I’d love to turn them into a blog post!