ACoS(Advertising Cost of Sales)
Also called: Advertising Cost of Sales, ad spend ratio
Definition
ACoS (Advertising Cost of Sales) is the Amazon Ads metric showing ad spend divided by ad-attributed sales revenue, expressed as a percentage. An ACoS of 30% means the publisher spent $30 in ads for every $100 of ad-attributed sales. For KDP coloring books, break-even ACoS is typically 35 to 45%, depending on price and print cost.
What is ACoS in Amazon Ads?
ACoS is the headline efficiency metric for Amazon Sponsored Products and Sponsored Brands campaigns. The formula is total ad spend divided by total ad-attributed sales, multiplied by 100 for percentage. An ACoS of 20% means 20 cents of ad spend per dollar of sales credited to ads.
What is a good ACoS for a coloring book?
For a KDP coloring book priced at $9.99 with a 60% royalty and roughly $2.30 in print cost, the publisher earns about $3.69 per sale. Break-even ACoS is around 37% on that book. A "good" ACoS is anything materially under break-even with stable conversion; campaigns at 20 to 30% ACoS are profitable, while 50%+ is bleeding money on every click.
How does ACoS relate to TACoS?
ACoS only measures ad-attributed sales. TACoS (Total ACoS) divides ad spend by total sales, including organic. A book with healthy organic sales can show high ACoS (because most sales are not ad-attributed) but a low TACoS (because the ad spend is a small share of total revenue). TACoS is the better north-star metric.
Why do new ad campaigns start at high ACoS?
Amazon's ad auction needs data to learn which keywords convert for a given book. New campaigns typically run at 60 to 100%+ ACoS for the first 7 to 14 days while Amazon explores the keyword space. The right move is to let the campaign collect 30 to 50 clicks per keyword before pruning underperformers, not to pause early on day-1 ACoS.
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Related terms
BSR
BSR (Best Sellers Rank) is Amazon's hourly-updated rank of every product against all others in its top-level store. For KDP coloring books, BSR sits in the Books store and approximates how recently a book sold. Lower number means more recent sales. BSR of 100,000 in Books equals roughly 2 to 3 sales per day.
KDP keyword
KDP gives every published title 7 keyword slots, each up to 50 characters, used by Amazon search to match queries to books. For coloring books, the slots should hold long-tail buyer queries ("coloring book for adults stress relief animals") not single words. Title, subtitle, and category placement also feed search but the 7 slots are the dedicated backend lever.
Royalty cliff
The royalty cliff is the discrete drop in royalty rate when a KDP paperback is priced outside the $2.99 to $9.99 standard distribution band. At $9.99 a standard-distribution paperback earns 60% royalty minus print cost. At $10.00+ the rate stays 60% on standard but the publisher loses access to certain promo tools and faces buyer resistance.