Keyword-level decisions beat campaign-level
Most KDP authors look at campaign ACoS and miss the fact that 10 keywords inside one campaign might be hugely profitable while 50 others bleed money. Running this calculator per keyword (using Amazon's search-term report) turns ads from gambling into engineering.
Scale, hold or pause framework
Scale: profit ≥ 30% of spend — double the bid and budget. Hold: profit positive but small — leave alone, check again in 14 days. Pause: profit negative after 10+ clicks — negative-match the term and remove. Run this loop weekly to compound returns.
Why conversion rate is king
A keyword converting at 12% can profitably tolerate a $1.20 CPC where a 4% keyword can't survive $0.40. Always check conversion rate before raising bids. If conversion is below 5% on a relevant keyword, the bottleneck is your product page — not the ad.
Finding hidden winners
Pull the search-term report monthly, filter for keywords with 5+ clicks and at least one sale, then plug each into this calculator. Convert the profitable ones to manual exact-match with custom bids. This single workflow is how seven-figure KDP authors compound ad ROI.
Frequently asked questions
How many clicks before I judge a keyword?
Minimum 10 clicks, ideally 25. Less is too small a sample.
What if conversion rate varies by keyword?
It always does — use the actual per-keyword CR from your search-term report, not a campaign average.
Should I bid above the suggested range?
Only if profit per click stays positive at the higher bid. Use this calc to back-test before raising bids.
Do I include royalty after print cost?
Yes — always use net royalty (after print/delivery) for true ROI.