Amazon Ads vs. BookBub vs. Facebook: Where Self-Published Authors Should Invest Their First $100

•StorySignal Team
book advertising comparisonmarketing budgetself-publishing adsAmazon vs BookBubauthor advertising

As a self-published author, your marketing budget is precious—especially when you're just starting out. That first $100 you allocate to advertising could be the difference between your book languishing in obscurity or finding its first loyal readers. But with so many advertising platforms available, where should you invest those limited dollars?

In this guide, we'll break down the three major advertising platforms for authors—Amazon Ads, BookBub, and Facebook—and help you decide which deserves your initial investment. We'll compare costs, targeting capabilities, learning curves, and potential returns to help you make an informed decision that aligns with your specific goals.

Understanding Your Options: The Big Three Explained

Before deciding where to spend your money, let's understand what each platform offers for self-published authors.

Amazon Ads: Direct Access to Book Buyers

Amazon Ads (formerly AMS or Amazon Marketing Services) allows authors to advertise directly on Amazon, the world's largest bookstore. Your ads appear in search results and on product pages of similar books, putting your title in front of readers who are actively looking to purchase.

Key Features:

  • Sponsored Products: Your book appears in search results and on product pages
  • Lockscreen Ads: Your book appears on Kindle lockscreens
  • Product Display Ads: Your book appears on related product pages
  • Minimum daily budget: $1 (though $5-10 is more realistic)

BookBub: Targeting Dedicated Readers

BookBub is a book discovery service with millions of dedicated readers who have specifically signed up to receive book recommendations. They offer two main advertising options: Featured Deals (highly competitive and expensive) and BookBub Ads (more accessible).

Key Features:

  • BookBub Ads: Display ads that appear in BookBub's daily emails
  • Precise targeting by author, genre, and retailer
  • CPM (cost per thousand impressions) bidding
  • Minimum campaign budget: $1 (though effectiveness starts around $10-20)

Facebook: Vast Reach Beyond Book Platforms

Facebook offers the largest audience of the three platforms, with sophisticated targeting options that extend beyond just book buyers. Your ads can appear in Facebook feeds, Instagram, and across their network.

Key Features:

  • Detailed demographic and interest-based targeting
  • Multiple ad formats (image, video, carousel)
  • Retargeting capabilities
  • Minimum daily budget: $1 (though $5 per day is more practical)

Making the Most of $100: Platform-by-Platform Breakdown

Now let's examine how your $100 might perform on each platform and which scenarios might favor one over another.

Amazon Ads: Best for Direct Sales

With Amazon Ads, your $100 can typically last 10-20 days at a conservative daily budget of $5-10. This platform offers the most direct path to sales, as you're advertising to people already on Amazon and in a buying mindset.

Pros:

  • Targets readers at the point of purchase
  • Direct integration with sales data
  • Can be effective with low bids (as low as $0.20-0.50 per click)
  • Immediate visibility on the world's largest bookstore

Cons:

  • Increasingly competitive, driving up costs
  • Somewhat cryptic reporting metrics
  • Requires ongoing optimization
  • Can burn through budget quickly without proper keyword research

Best for: Authors with books in Kindle Unlimited, those launching a series, or those with multiple books who can benefit from sell-through.

BookBub Ads: Best for Targeted Reader Exposure

BookBub's highly targeted audience means your $100 can reach very specific readers. A typical campaign might cost $10-20 per day, so your budget would last approximately 5-10 days.

Pros:

  • Highly engaged audience of confirmed readers
  • Excellent targeting by comparable authors
  • Visual creative options
  • Good for promoting limited-time deals

Cons:

  • Smaller reach than Amazon or Facebook
  • Can be expensive for popular genres/authors
  • Learning curve for effective creative design
  • Limited to email placement (not on-site advertising)

Best for: Authors promoting a price promotion, those with an established comparable author to target, or those launching in popular genres with clear reader preferences.

Facebook Ads: Best for Building Author Awareness

On Facebook, $100 can potentially reach thousands of people. With a daily budget of $5, your campaign could run for about 20 days, though results may vary widely based on your targeting.

Pros:

  • Largest potential audience
  • Sophisticated targeting options beyond just "readers"
  • Great for building mailing lists
  • Ability to retarget website visitors

Cons:

  • Not directly connected to book purchasing
  • Requires compelling creative and copy
  • Changing privacy policies affecting targeting
  • Can be difficult to track ROI precisely

Best for: Authors building a brand, growing a mailing list, promoting a series, or those with books in wider genres that appeal to specific interest groups.

Where Should You Invest Your First $100?

Based on my experience helping authors navigate advertising platforms, here's my recommendation for where to invest your first $100:

Amazon Ads for Most Self-Published Authors

For most self-published authors, Amazon Ads offers the best starting point for your first $100. Here's why:

  1. Direct sales potential: You're advertising directly where books are sold
  2. Lower entry barrier: You can start with small daily budgets ($5) and modest bids
  3. Learning opportunity: The platform provides immediate feedback on which keywords drive impressions and sales
  4. Scalability: As you learn what works, you can gradually increase investment

Here's how to allocate your first $100 on Amazon Ads:

  • $70: Launch a Sponsored Products campaign targeting keywords
  • $30: Launch a second Sponsored Products campaign targeting similar authors/books

Action steps for Amazon Ads success:

  1. Research 30-50 relevant keywords using Amazon's search bar and tools like Publisher Rocket
  2. Set up a Sponsored Products campaign with automatic targeting to gather data
  3. Start with low bids ($0.25-0.35) to stretch your budget
  4. After gathering data, create a manual campaign with your best-performing keywords
  5. Focus on your click-through rate and conversion rate, not just impressions

When to Consider the Alternatives

While Amazon Ads works for most, certain situations might favor the other platforms:

Consider BookBub If:

  • You have a limited-time promotion or price drop
  • Your book clearly aligns with specific, well-known authors in your genre
  • You have strong cover art that will stand out in BookBub's visual format
  • Your genre performs particularly well on BookBub (romance, mystery, thrillers)

Consider Facebook If:

  • Your primary goal is building a mailing list rather than immediate sales
  • Your book appeals to specific interest groups beyond typical genre readers
  • You have a strong author brand or personality to showcase
  • You have engaging content or videos to share alongside your book promotion

Maximizing ROI: Platform-Specific Tips

Whichever platform you choose, here are some tips to maximize your return on investment:

Amazon Ads Tips:

  • Focus on relevant keywords with commercial intent
  • Use negative keywords to avoid wasting budget
  • Start with automatic campaigns to discover converting keywords
  • Keep your Average Cost of Sale (ACoS) below 70% for sustainable ads

BookBub Tips:

  • Test different images and backgrounds for your ads
  • Target authors whose readership closely aligns with yours
  • Schedule ads to run when your target audience is most active
  • Focus on regions where your book sells best

Facebook Tips:

  • Create a landing page rather than linking directly to Amazon
  • Use video when possible—it typically has lower cost per click
  • Test multiple ad variations with different images and copy
  • Build custom audiences based on your website visitors or mailing list

Conclusion: Start Small, Learn Fast

Your first $100 in advertising is as much about education as it is about sales. Amazon Ads provides the most direct path to reaching readers ready to buy, making it the ideal starting point for most self-published authors.

Remember that advertising is a long-term strategy. The data you gather from your first $100 will inform how you spend your next $100, helping you refine your approach and gradually increase your return on investment.

Whichever platform you choose, approach it with patience and a willingness to learn. Track your results, adjust your strategy based on data, and don't be discouraged if your first campaign doesn't immediately pay for itself. The knowledge you gain is an investment in your author career.

Are you ready to invest your first $100 in book advertising? Start with the platform that best aligns with your specific goals, and remember that consistency and learning from your results will ultimately lead to advertising success.

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