PageTally pagetally.co
Free tool · For KDP Select authors
If you are in Kindle Unlimited and write in series, the ACOS on your ads dashboard is measuring a fraction of what a click actually earns you. Enter seven numbers and see the rest.
Everything here is in your KDP dashboard and your Amazon Ads export. Nothing is sent anywhere — the maths runs in your browser.
A campaign pays for itself when revenue per click beats the price you paid for that click. Everything else is noise.
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Reported ACOS
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True ACOS
Enter your numbers above.
One reader, acquired on book 1. Each bar is what that reader is worth across the series — solid where Amazon can see it, hatched where it cannot.
A borrow is worth your billable KENPC multiplied by the monthly page rate and by how much of the book gets read. A sale is worth your list price at 70% or 35%, minus the delivery fee. Blend the two by your purchase share and you get what one acquired reader is worth on book 1. Apply your read-through rate down the series and you get the whole picture.
The 0.70 is deliberate. Ad traffic finishes books and continues series less reliably than readers who came looking for you. Discounting the modelled part by 30% keeps this number defensible when you act on it.
Two of these inputs — completion rate and read-through — are estimates. Amazon publishes neither. Treat the result as a prudent floor, not a promise, and confirm it by pausing a campaign for a week and watching what happens to your page reads.
The spreadsheet runs this across your whole catalogue and every campaign, and returns a cut-or-scale verdict for each one. I send an updated copy whenever the KENP rate moves.
One email when the rate updates. Unsubscribe in a click.