The full ad funnel
Profit on Amazon Ads is the product of four numbers: impressions × CTR × conversion rate × royalty, minus clicks × CPC. Optimizing any one of these compounds the others. A 0.1% CTR improvement can multiply final profit by 25% in a campaign with thousands of impressions.
Benchmark conversion rates
Healthy KDP product pages convert 8–15% of clicks on relevant keywords. Below 5% suggests cover, blurb or pricing problems. Above 20% usually means very tight keyword targeting (branded or series terms). Test cover variations and the first three lines of your description to lift conversion.
CPC by category
Romance and thrillers run $0.20–$0.40 CPCs because of high author competition. Business, self-help and how-to often hit $0.80–$1.50 CPC on top keywords. Children's books vary wildly; picture-book keywords can spike to $2 during back-to-school season. Always check the suggested bid range Amazon shows in campaign manager.
Scaling profitable campaigns
Once a campaign clears 30% profit margin over 14 days with at least 50 clicks, double the daily budget and observe for another 14 days. Stop scaling once profit-per-click stops growing — you've found the diminishing-returns ceiling for that keyword set. Then build a new campaign in a sibling category.
Frequently asked questions
What CTR should I expect on KDP ads?
0.3–0.6% on broad campaigns, up to 1.5% on tight keyword targeting.
Why are my impressions so high but clicks low?
Cover or title isn't compelling on the search results page. Test a new cover thumbnail before raising bids.
Is profit per click the most important metric?
Yes for steady-state campaigns. For launches, total units sold matters more because of the rank effect.
Should I use auto or manual campaigns?
Start with auto to harvest converting search terms, then graduate winners to manual exact-match for tighter control.