Amazon PPC for Authors: How Book Ads Work

Amazon’s guide to cost per click says PPC and CPC describe the same thing, and its advertising FAQ says you are charged for clicks, not for impressions. For books, KDP’s help page on advertising for KDP books says Sponsored Products are cost-per-click: you pay only when customers click your ad, and you choose your bid per click and your own budget.

Amazon’s Sponsored Products page adds that there are no monthly or upfront fees. The click takes the reader to your book’s detail page, as Amazon’s author’s guide to Sponsored Products notes, and that page has to make the sale.

• You earn a royalty, not the price. Ad sales count the price of the books sold, but your share is the royalty: for a paperback, the royalty rate times the list price, minus printing. Amazon’s ACOS guide says ACOS has to stay below your profit margin, which for a book is the royalty divided by the price.
• Page reads sit outside ad sales. An ebook in KDP Select is automatically included in Kindle+ (formerly Kindle Unlimited), the subscription Amazon renamed in October 2026. KDP Help says ad sales leave out Kindle+ pages read; the ads console estimates those pages and their royalties separately, for pages read within 14 days of a click.
• Read-through stays out of the campaign. KDP Help says sales of the advertised ASIN are the ones credited to the campaign. A reader who starts with book one and buys the rest of the series adds only book one, so an opening book can look worse in Amazon Ads than it is.
• Sponsored Brands works without Brand Registry. Amazon’s FAQ asks sellers to be enrolled in Brand Registry; its guide to Sponsored Brands for authors asks instead for three or more eligible titles claimed under the same author name.
• Book ads are reviewed first. Amazon’s guide to advertising books says review typically takes 24 hours and can take up to three business days, and the book must be available in the country where you advertise it.

KDP Help describes two ad types for books, Sponsored Products and Sponsored Brands, and Amazon’s book ads page says both charge per click. KDP titles can be advertised in twelve marketplaces: the US, Canada, Mexico, the UK, Germany, Italy, Spain, France, the Netherlands, India, Australia and Japan. Audiobook ads are US-only for now.

Sponsored Products is the place to start, because it works with a single book. Our guide to Sponsored Products for books covers targeting, match types and a first campaign, and our guide to profitable Amazon ads for books suggests a campaign structure for each title.

Sponsored Brands suits a series or a backlist. Amazon’s guide for authors lists two formats: video, and collections of 3 to 10 of your books in one ad. Its reporting guide for book advertising lists the US, Canada, the UK, Germany, France, Italy, Spain and Australia for KDP authors; the book ads page names six of them, without Canada and Australia. Check your own console.

Display and lockscreen ads sit outside what KDP Help describes. Amazon now calls Sponsored Display “display ads”, and the table above sums up what its pages say about both. The rest of this guide sticks to Sponsored Products and Sponsored Brands.

A bid, in the words of Amazon’s author’s guide, is the price you are willing to pay for a reader to click your ad. Several authors may bid on the same keyword, and the bid together with the ad’s relevance to the search decides whose ad shows.

The bid is a ceiling, not the price. Amazon’s FAQ calls it the maximum you are willing to pay when a customer clicks, and its CPC guide says the final cost per click is usually set by the auction, from your adjusted bid plus other factors. Busier keywords and more visible placements generally cost more, and there is no set price per click. “Adjusted” means after the bidding strategy and placement adjustments in the next section.

The daily budget is the most you want to spend on clicks per day, averaged over the month: the author’s guide says $10 a day for 30 days never spends more than $300. Budgets are not paced through the day, Amazon’s Sponsored Products page adds, so a small one can be gone in minutes. The minimum for Sponsored Products is $1 a day, according to the FAQ, and the best-practice guide recommends starting at $10.

To size a budget, count clicks. At $10 a day and $0.40 a click, two weeks buy about 350 clicks, enough to see roughly how a book converts. Across a catalog, give each book its own budget and put more behind the books that can afford more per click, a number the break-even section below shows how to find.

Each Sponsored Products campaign has a bidding strategy that decides whether Amazon may change the bid you entered, and in which direction. Amazon’s author’s guide describes three; the last column is our advice.

Up and down needs room. Amazon’s guide to dynamic bidding tells you to be prepared to potentially spend double the bid you enter. Amazon’s pages differ on the limit outside the top of search, 50% in the author’s guide and 100% in the bidding guide, so plan for double. A bid that already sits at the book’s break-even cost per click loses money on a doubled click even when it sells. Set the base bid at half the line or stay on down only: for the paperback below, which breaks even near $0.40 a click, that is about $0.20.

Placement adjustments come on top. Amazon’s announcement of the rest-of-search adjustment names three placements, top of search (first page), rest of search and product pages, each adjustable by up to 900% under any bidding strategy. The placement report compares top of search with the rest, so you can see whether the top spot earns its price.

Sponsored Brands works differently: Amazon’s guide for authors describes automated bidding for placements below top of search, based on conversion rates, and it does not apply to video ads.

Three numbers show where a book’s break-even line sits.

1. Royalty per sale. KDP’s Paperback Royalty page gives (royalty rate × list price) − printing cost, with a 60% rate on Amazon.com at $9.99 and up. A 250-page black-ink paperback at $14.99 costs $1.00 + 250 × $0.012 = $4.00 to print and earns 60% × $14.99 − $4.00 = $4.99. On the 70% plan, an ebook earns 70% of the list price after VAT and a delivery cost of $0.15 per MB on Amazon.com, within a price band of $2.99 to $12.99: $3.28 at $4.99 with a 2 MB file.
2. Break-even ACOS. Royalty divided by list price: 33.3% for the paperback, 65.7% for the ebook. Above it, each ad sale costs more in clicks than it earns. Our guide to what ACOS is explains this line in depth.
3. Break-even cost per click. Royalty times conversion rate, which is orders divided by clicks in your campaign report. If 8% of clicks buy, a sale takes 12.5 clicks, and the paperback breaks even at $4.99 × 8% = $0.40 a click. It is the same line as break-even ACOS: 33.3% × $14.99 × 8% is also $0.40.

Here are both books side by side, at two example conversion rates.

The ebook can carry about twice the ACOS of the paperback, yet the paperback can pay more per click, because each sale brings in more money. So set bids in money per click. The conversion rates here are examples; yours come from your own reports and differ by book, keyword and placement.

Now a real month: the paperback’s campaign had 200 clicks and 16 sales, an 8% conversion rate. At an average of $0.35 a click it spent $70 and earned $79.84 in royalties: $9.84 of profit at 29.2% ACOS. At $0.50 a click, the same clicks and sales would have cost $100, a loss of $20.16 at 41.7% ACOS.

For your own books, the KDP royalty calculator gives the royalty, the ACOS calculator turns it into a break-even ACOS, and the Amazon Ads cost calculator shows what a daily budget, cost per click and conversion rate add up to in a month.

Two things raise the line. For an ebook in KDP Select, add the estimated KENP royalties the ads console attributes to the campaign; the KENP calculator turns pages into money at a rate you choose. For the first book in a series, the series read-through calculator works out what a reader who starts with book one earns you across the series: the most you can spend per sale of book one.

Amazon’s best-practice guide suggests checking a new campaign at least twice a week in its first week. The author’s guide suggests waiting about two weeks before getting more advanced with bids, then checking in every two weeks. We keep that rhythm for bids and read search terms weekly:

1. Count complete days only. KDP Help says orders can take up to 12 hours to reach your advertising report, so leave today out.
2. Read the search term report. It lists the searches that led to at least one click on your ad, according to Amazon’s reporting guide. Sort it by spend.
3. Block searches that spend without selling. Add them as negative exact or negative phrase keywords, for a campaign or selected ad groups, as Amazon’s targeting guide describes; it suggests judging a keyword after at least 20 clicks. We also look at money: a search that has cost about twice the book’s royalty without a sale has had its chance, which for the paperback is about $10, or 25 clicks at $0.40. Searches plainly not about your book can go at once.
4. Promote searches that sell. Amazon’s best-practice guide suggests raising the bid on searches with higher sales and conversion rates and adding them as exact-match keywords.
5. Every other week, move bids toward each book’s line. Compare each keyword’s average cost per click (spend divided by clicks) with the book’s break-even cost per click. To size a cut, multiply the bid by break-even ACOS ÷ current ACOS: a paperback keyword at 45% ACOS with a $0.50 bid drops to about $0.37. Raise bids on keywords that sit well under the line but get few impressions.
6. Check placements and budgets. Raise a placement adjustment only where that placement sells under break-even. If a campaign keeps running out of budget, the best-practice guide says to add budget so the ads keep showing. We do that only for campaigns under their line and fix the bids on the rest first.

The Amazon Ads console shows the ad side: spend, clicks, cost per click, ad sales and ACOS by campaign, keyword and search term, plus estimated KENP pages and royalties for Sponsored Products. It counts only sales attributed to your ads within 14 days of a click.

KDP Reports show the royalty side: every sale and page read, whatever led to it. KDP Help also notes a timing gap: KDP records a paperback when it ships, Amazon Ads on the day it was bought. Our guide to KDP reports explains which report holds the final monthly royalty.

Profit per book is each book’s KDP royalties minus its ad spend, month by month. Amazon’s author’s guide also suggests watching TACoS, total advertising cost of sales: ad spend as a percentage of all of a book’s sales. A spreadsheet with one row per book and month does the job.

SelfPub Go can do the joining for you. Its Amazon PPC tools for authors read every campaign against a break-even ACOS worked out from each book’s own royalty, price, format and marketplace, and royalty analytics reads the KDP report you already download, so profit per book after ads sits next to the campaigns behind it.

Rules, limits and formulas in this guide come from KDP Help and Amazon Ads as of the date at the top of the page, on Amazon.com prices. The conversion rates and the thresholds in the routine are ours. If something here no longer matches, trust the linked pages.