Amazon Ads for Authors: Start Selling Your Book with Paid Advertising
Mastering Amazon Ads can turn a self-published book into a revenue-generating asset. This guide covers Sponsored Products, targeting, and the one thing that makes ads work: reviews.
Types of Amazon Ads for Authors
Amazon offers three ad formats for KDP authors. Most authors should start with Sponsored Products.
Sponsored Products
The most powerful ad type for authors. Your book appears in Amazon search results and product pages. Pay per click (PPC). Most authors start here. Works best with 10+ reviews.
Sponsored Brands
Shows your author logo and up to 3 books at the top of search results. Requires Brand Registry. Best for authors with 3+ titles in a series or related books.
Lockscreen Ads
Shows on Kindle device lock screens for Kindle Unlimited books. Lower CPCs, great for KU authors. Requires KDP Select enrollment.
Auto vs. Manual Targeting
Understanding this distinction is the single biggest leverage point in KDP advertising.
Auto Targeting
Amazon chooses who sees your ad based on your book's content and metadata. Good for research — run for 2–4 weeks to discover which keywords convert. Set a low bid ($0.20–0.35). Requires no keyword research upfront.
- ✓ No keyword research needed
- ✓ Great for gathering data
- ✓ Lower risk while learning
Manual Targeting
You choose specific keywords, ASINs, or categories. Better ROI when done right. Use data from auto campaigns to choose winning keywords. Two subtypes: keyword targeting (broad/phrase/exact) and product targeting (specific ASINs or categories).
- ✓ Higher ROI potential
- ✓ Precise audience control
- ✓ Target competitor ASINs
The #1 Reason Amazon Ads Fail for Authors
No reviews. Amazon's ad algorithm amplifies books that convert — and books without reviews don't convert. Running ads on a book with 0–3 reviews wastes budget regardless of how well-targeted your campaign is.
The sweet spot: 10+ reviews before spending seriously on ads. Even moving from 0 reviews to 10 reviews can multiply your ad conversion rate by 5x.
Get Reviews Before Launching AdsHow to Set Up Your First Sponsored Products Campaign
Follow these six steps to launch your first KDP ad campaign the right way.
Open the KDP Ads Dashboard
Go to KDP → Marketing → Amazon Ads → Create Campaign.
Choose Campaign Type
Select "Sponsored Products" as your campaign type. This is the standard ad format for book search results.
Select Your Book ASIN
Choose the specific book you want to advertise. If you have multiple editions (ebook + paperback), create separate campaigns for each ASIN.
Start with Auto Targeting
Set a daily budget of $5–$10 and choose auto targeting for your first campaign. Let Amazon gather data before you switch to manual.
Set Your Default Bid
Set a default bid of $0.25–$0.40. This is competitive enough to get impressions without overpaying early on. Adjust after 2 weeks based on your data.
Review After 14 Days
After 14 days, analyze your search term report. Disable any keywords with more than 6 clicks and zero sales. Move converting keywords to a manual campaign with slightly higher bids.
KDP Ads Bidding Strategy
Bidding is where most authors either over-spend or under-invest. These four principles keep your campaigns profitable.
Start low and raise on converters
Set default bids at $0.20–$0.40 and raise bids only on keywords that are already converting. Never raise bids on keywords with clicks but no sales.
Calculate your break-even ACoS
Your break-even ACoS = royalty ÷ sale price × 100. If your royalty is $3.50 on a $4.99 book: 70% ACoS is break-even. Anything below 70% is profit.
Target 30–50% ACoS for profitability
Aim for 30–50% ACoS depending on your pricing tier. Lower is better, but too-low ACoS often means your bids are too low to win enough impressions.
Prioritize long-tail keywords
Long-tail keywords (3–4 words) like "dark fantasy romance kindle unlimited" usually have lower CPCs and higher conversion rates than broad terms like "fantasy books".
Why Reviews Supercharge Your Ads ROI
The difference in ad efficiency between a book with no reviews and one with 25+ reviews is dramatic. Here's the same $100 ad budget at two different review counts:
Getting reviews before running ads is the highest-ROI action you can take. iWrity connects your book with matched readers who leave genuine Amazon reviews.
Build Your Review Base with iWrityFrequently Asked Questions
How much should I spend on Amazon Ads as a new author?+
Start with $5–$10 per day for your first campaign. This gives you enough data over 2–4 weeks to identify which keywords convert without burning your budget. Resist scaling up until you have winning keywords and at least 10 reviews.
Do I need Brand Registry to run Amazon Ads?+
No. Sponsored Products campaigns are available to all KDP authors without Brand Registry. Brand Registry is only required for Sponsored Brands ads, which show your author logo and up to 3 books at the top of search results.
What is ACoS and what is a good ACoS for book ads?+
ACoS (Advertising Cost of Sale) is your ad spend divided by ad revenue as a percentage. Your break-even ACoS equals your royalty divided by your sale price. For a $4.99 ebook earning $3.50, break-even is 70%. Target 30–50% ACoS for genuine profitability.
Should I run auto or manual Amazon Ads campaigns first?+
Start with auto targeting. Run it for 2–4 weeks at a low bid ($0.20–$0.35) to discover which keywords convert. Then create a manual campaign using the best performers from your auto campaign data.
When is the right time to start running Amazon Ads?+
When your book has at least 10 reviews. Books with few or no reviews have very low conversion rates regardless of ad spend. Get reviews first via an ARC campaign, then launch paid ads.