SelfPub Go vs Perpetua
Of everything we reviewed in August 2026, Perpetua is the closest thing to both halves of an author’s money in one product: it automates Amazon advertising properly, and it documents three KDP metrics built on KENP. It is also “retail media optimization software” in its own words, sold to sellers, brands and agencies from $695 a month as of August 2026, and the KDP figures it documents are estimates attributed to its own ads. Below is where the line falls — with a link to Perpetua’s own page next to every claim we make about it.
Facts checked 21 August 2026. Documentation changes; if something here is out of date, tell us and we will correct it.
What Perpetua is good at.
Advertising automation, and it is real automation. Perpetua automates Amazon advertising: “With bids automatically being adjusted daily to meet your target ACOS you can rest easy knowing your campaigns are running as efficiently as possible.” Its advertising page promises to “Create, launch and optimize Sponsored Ads in seconds” and names Sponsored Brands, Sponsored Brands video, Sponsored Display and Amazon DSP.
It also thought about books early. On 3 March 2021 Perpetua announced three KDP-specific metrics — KENP Reads, Estimated KENP Royalties and ACOR (Advertising Cost of Royalties) — and its help center defines the metric as “ACOR (Advertising Cost of Royalties) = The percent of Royalties spent on advertising. (Spend/KENP Royalties).” Spend divided by royalties, rather than by retail price, is the ratio a book actually runs on. We think that is the right idea, and it is the same idea SelfPub Go is built around.
And the speed argument does not run in our favor here. On Perpetua’s pricing page, “Hourly Reporting & Intraday Optimization via Amazon Marketing Stream” is listed from the Growth tier upward, not on the entry Essentials tier. Its Stream documentation describes hourly ad performance data and does not mention KENP or KDP metrics. Hourly advertising data through Amazon’s Marketing Stream is the same architecture our own real-time view is built on, so “we are fresher” is not a claim we will make against them.
Perpetua is also unusually transparent about the quality of its own numbers. It publishes that its KENP royalties are an estimate, that attribution can take up to 14 days, that offline page reads can take a week, and that the KENP rate moves every month. Vendors are not obliged to tell you any of that.
SourcePerpetua — Amazon advertising softwarePerpetua blog — Introducing KENP metrics for KDP authors (3 March 2021)Perpetua help — Amazon KDP: what is ACOR? (updated 31 October 2024)Perpetua — PricingPerpetua help — How to access Stream (updated 17 February 2026)checked 21 August 2026
Where it stops, for an author.
None of this is a flaw in Perpetua. It is a product built for a different buyer, and the consequences of that show up in who it documents, what its book numbers cover and what it costs to get in. Everything below is quoted from its own site or help center, dated, and never stated more strongly than the source states it.
The audience it names is sellers, brands and agencies
Perpetua's homepage describes the product as “retail media optimization software,” names Amazon and Walmart as marketplaces, names sellers, brands and agencies as its audiences, and displays an “Amazon Advanced Partner” badge. Its named customers are consumer brands — Crocs, Hero Cosmetics, Ready, Set, Food! — not authors or publishers. That is the audience it writes for, which shapes the onboarding, the vocabulary and the size of the ad budget the product assumes.
SourcePerpetua — homepagechecked 21 August 2026
The KDP figures it documents are the ones its own ads produced
Perpetua's KENP figures are ad-attributed only, by its own definition: KENP Read is “The estimated number of pages read by Kindle Unlimited customers attributed to your ads.” Books also sell and get read for reasons no click touched, and that half of the month sits outside those three documented metrics. What else the product puts in front of an author beyond them, we do not know — we have had no hands-on access.
SourcePerpetua help — Why KENP Read and KENP Royalties are estimated metrics (28 May 2021)Perpetua blog — Introducing KENP metrics for KDP authors (3 March 2021)checked 21 August 2026
Those royalties are an estimate, and the rate moves every month
Perpetua states KENP Royalties are “calculated by multiplying KENP read by the KENP rate at the time the pages were read,” and warns: “The KENP rate changes every month, so your actual royalties when the fund is announced may differ from the estimation.” It documents the lag in the same article: Amazon “attributes them to the reading events for the same titles up to 14 days after customers click the ad,” and “Pages read from offline devices can take 1 week to be reported.” Publishing that openly is to its credit — it is also a different kind of number from the one in your KDP report.
SourcePerpetua help — Why KENP Read and KENP Royalties are estimated metrics (28 May 2021)checked 21 August 2026
The documented account types are Seller and Vendor
Perpetua's Account Connection Guide (last updated 6 February 2026) documents two account types only — Seller (Amazon Advertising API plus Selling Partner API) and Vendor (Amazon Advertising API) — and requires that the connecting Amazon login has “Admin Permissions” on the Campaign Manager plus active advertising campaigns. As of 21 August 2026, its nine-article “Account Connection” help collection contained no article about KDP, Kindle or authors. That is what their published documentation covers, and it is not the same statement as what the product can technically connect.
SourcePerpetua help — Account Connection Guide (updated 6 February 2026)Perpetua help — Account Connection collectionchecked 21 August 2026
The documented way in is a demo, then up to 48 hours of syncing
Perpetua's own onboarding article (last updated 31 March 2026) opens with “Visit perpetua.io and click on any of the two ‘Book a Demo’ buttons,” and states “The syncing process will take up to 48 hours.” Its homepage offers no other documented entry point. An undocumented self-service path may well exist; we did not find one, which is a fact about their documentation rather than about their product.
SourcePerpetua help — [Sellers] How do I connect my Amazon account? (updated 31 March 2026)Perpetua — homepagechecked 21 August 2026
On the pages that sell it, the day we looked, KDP was not there
As of 21 August 2026, Perpetua's homepage, its Amazon advertising software page and its pricing page contained no mention of KDP, Kindle, books or authors, and its pricing page listed no author-specific tier. We found no Perpetua announcement about KDP newer than its March 2021 posts; its two KDP help articles date from May 2021 and October 2024. We are reporting a dated reading of public pages — nothing about their roadmap, and no claim in either direction about which accounts they onboard today.
SourcePerpetua — homepagePerpetua — Amazon advertising softwarePerpetua — PricingPerpetua blog — Introducing KENP metrics for KDP authors (3 March 2021)checked 21 August 2026
The published price, in full
As of August 2026 Perpetua’s published pricing is: Essentials “$695/mth” for “Up to 10k in monthly ad spend”; Growth “$695/mth + % of ad spend” for “Over 10k in monthly ad spend”; Premium “Custom” for “Over 500k in monthly ad spend.” Its pricing page lists no KDP, Kindle, book or author tier. On the question of a trial, its own page is silent; Capterra’s Perpetua listing states a starting price of $695.00 per month and marks both Free Trial and Free Version as “Not available” (Capterra, checked August 2026).
What an individual author would actually be quoted, we do not know, and we are not going to invent it. Published tiers are what a vendor prints; what lands in a contract after a demo call is something only Perpetua can tell you.
SourcePerpetua — PricingCapterra — Perpetua pricing listingchecked 21 August 2026
What SelfPub Go does differently.
Not more automation — a smaller subject. Perpetua optimizes retail media for the companies that buy it. SelfPub Go answers one author’s question: what did this book earn, what did the ads for it cost, and am I ahead this month.
The denominator is your royalty, on every sale
SelfPub Go recomputes ACOS against what a sale actually pays you — royalty rate, format, marketplace, delivery cost — and counts KENP page reads as income whether an ad touched them or not. A campaign that looks expensive against the cover price can be comfortably profitable once the royalty is the divisor, and the reverse happens just as often.
One Amazon connection, no Seller Central needed
SelfPub Go authorizes your Amazon Ads account through Amazon's own OAuth screen and reads campaigns through the official Advertising API. Royalty data comes from the KDP reports Amazon already gives you, parsed on your own machine.
Nothing changes without your approval
Bid moves and negative keywords arrive as proposals with the numbers behind them. At author-sized budgets a single unattended bid change is a meaningful share of the month, so nothing executes on its own.
Sized for one person and a shelf of books
The workflow assumes a handful of titles across several marketplaces and formats, one person making the decisions, and an ad budget where every dollar has a name. Royalty reports are parsed and stored on your own computer and never uploaded to us.
That is our claim about our own product, not a checked comparison. The roadmap lists what is live today and what is not.
SelfPub Go vs Perpetua, row by row.
The Perpetua column is what its own site and help center said on 21 August 2026. Where its documentation is silent, this table says so rather than guessing.
| Perpetua | SelfPub Go | |
|---|---|---|
| What it is | “Retail media optimization software,” in its own words, naming Amazon and Walmart as marketplaces and sellers, brands and agencies as its audiences. | A desktop app for macOS and Windows, built around one author's catalog. |
| Campaign management | Automated: “With bids automatically being adjusted daily to meet your target ACOS you can rest easy knowing your campaigns are running as efficiently as possible.” Its advertising page promises to “Create, launch and optimize Sponsored Ads in seconds” and names Sponsored Brands, Sponsored Brands video, Sponsored Display and Amazon DSP. | Sponsored Products, Sponsored Brands and Sponsored Display in one table, with bulk bid edits, search-term reports and negative keywords. Suggested changes wait for your approval. |
| KDP metrics documented | Three, announced on 3 March 2021: KENP Reads, Estimated KENP Royalties and ACOR — “ACOR (Advertising Cost of Royalties) = The percent of Royalties spent on advertising. (Spend/KENP Royalties).” | Royalty by book, format and marketplace from your own KDP reports, KENP page reads counted as income, refunds deducted, profit per book per day. |
| Where those book numbers come from | Ad attribution: KENP Read is “The estimated number of pages read by Kindle Unlimited customers attributed to your ads,” and KENP Royalties are “calculated by multiplying KENP read by the KENP rate at the time the pages were read.” | The KDP royalty report itself, joined to spend from Amazon's Advertising API, per book and per day. |
| Documented account types | Seller and Vendor. As of 21 August 2026 its nine-article “Account Connection” help collection contained no article about KDP, Kindle or authors. | One Amazon Ads authorization through Amazon's own OAuth screen. No Seller Central account involved. |
| Hourly ad data | “Hourly Reporting & Intraday Optimization via Amazon Marketing Stream” is listed from the Growth tier upward on its pricing page, not on the entry Essentials tier. Its Stream documentation describes hourly ad performance data and does not mention KENP or KDP metrics. | Ads data in real time. Royalties on each report import. |
| Getting started | “Visit perpetua.io and click on any of the two ‘Book a Demo’ buttons,” per its onboarding article, and “The syncing process will take up to 48 hours.” | Closed early access: you apply, we reply. No demo call required. |
| What it costs | As of August 2026: Essentials “$695/mth” for “Up to 10k in monthly ad spend”; Growth “$695/mth + % of ad spend” for “Over 10k in monthly ad spend”; Premium “Custom” for “Over 500k in monthly ad spend.” Its pricing page lists no KDP, Kindle, book or author tier. | Nothing to buy. SelfPub Go is in closed early access and there is no checkout. |
| Who is behind it | Perpetua now operates under the Flywheel brand — Flywheel's own retail media page markets “Perpetua-powered automation” and links its investor page to Omnicom Group. Omnicom agreed on 30 October 2023 to acquire Flywheel Digital “for a net cash purchase price of approximately $835 million,” and announced the closing of that acquisition on 2 January 2024. | A small independent team building one product. |
Perpetua figures and quotations come from the pages listed at the bottom of this page, checked 21 August 2026. Prices move — check theirs before you decide.
Which one should you use?
These two rarely land on the same desk, and pretending they compete for every reader would be the dishonest version of this page.
Look at Perpetua if…
- Your Amazon advertising is a company line item rather than a book budget — its published entry tier is $695 a month for up to 10k in monthly ad spend, as of August 2026.
- You want daily automated bidding to a target ACOS, across formats up to Amazon DSP.
- You sell as a Seller or a Vendor — the two account types its connection guide documents.
- A demo call and up to 48 hours of initial syncing are a normal way to start a tool.
Use SelfPub Go if…
- You are the author, the publisher and the media buyer, and there is no agency between you and the campaigns.
- Most of your income arrives as KDP royalties and KENP page reads, and you need profit per book rather than impressions.
- You want every page read counted, not only the reads attribution assigned to an ad.
- You would rather your royalty files never left your own computer.
Ask Perpetua directly if…
- You want to know whether they onboard KDP accounts today — their public documentation did not settle it for us, and we will not guess on their behalf.
- You want a number for a single author: their published tiers start at $695 a month as of August 2026, with no author tier listed.
- You need to know which marketplaces their KDP metrics cover, or whether there is a trial. Both are unknown to us.
SourcePerpetua — PricingPerpetua help — Account Connection Guide (updated 6 February 2026)Perpetua help — [Sellers] How do I connect my Amazon account? (updated 31 March 2026)checked 21 August 2026
Why this comparison is the interesting one.
Among the tools we checked in August 2026, the author-facing tools and the Amazon advertising tools sit on opposite sides of the author’s money. Book Report and ScribeCount report royalties and read advertising data, but their own documentation describes no way to manage campaigns, bids or keywords. Ad Badger manages Amazon advertising properly, but is built for sellers and tracks no author royalties or KENP. Publisher Rocket works before publication and mentions no royalties or KENP at all. The one tool we found carrying both halves on paper — Perpetua — is sold to sellers, brands and agencies from $695 a month as of August 2026, and the only KDP figures it documents are estimates attributed to ads.
That is the gap SelfPub Go is being built into, and Perpetua is the product that defines its edges. The sourced comparisons against the others are here: Book Report, ScribeCount, Publisher Rocket and BookBeam.
SourceBook Report docs — Amazon AdsScribeCount — FeaturesAd Badger — Product tourPublisher Rocket — homepagePerpetua — PricingPerpetua help — Why KENP Read and KENP Royalties are estimated metrics (28 May 2021)checked 21 August 2026
Questions we get asked about Perpetua.
Does Perpetua work with KDP books?
Ask them — we are not going to answer that for you in either direction, because our reading of their public pages does not settle it. What we can show you: on 3 March 2021 Perpetua announced three KDP-specific metrics (KENP Reads, Estimated KENP Royalties and ACOR), and its help center still defines ACOR as “The percent of Royalties spent on advertising. (Spend/KENP Royalties).” Against that, its Account Connection Guide of 6 February 2026 documents Seller and Vendor accounts only, and on 21 August 2026 its nine-article Account Connection collection contained no article about KDP, Kindle or authors. We found no Perpetua announcement about KDP newer than March 2021. Those are dated observations about documentation, not a claim about what the product does today.
What does the Amazon Advertising API allow for KDP authors?
According to Perpetua's own help center (December 2023), “The Amazon Advertising API allows integrators to read and make changes to advertising campaigns for both sellers, vendors and KDP authors,” and to revoke access “For vendors and KDP Authors, this would be done via the Amazon Advertising console.” Read that for what it is: a statement about what Amazon's API permits any integrator to do, not a statement about which accounts Perpetua connects today. SelfPub Go reads campaigns through that same official Advertising API, authorized on Amazon's own OAuth screen.
Is SelfPub Go's data fresher than Perpetua's?
No, and we are not going to pretend otherwise. Perpetua's own documentation covers hourly ad performance through Amazon Marketing Stream — the same architecture our real-time view is built on — and on its pricing page that hourly reporting is listed from the Growth tier upward rather than on the entry tier. Speed is not our argument against Perpetua. Who the product is written for, what the book-side numbers cover, and what it costs to get in the door are.
Can SelfPub Go replace Perpetua?
Not for the work Perpetua is sold to do. Daily automated bidding to a target ACOS across Sponsored Brands, Sponsored Brands video, Sponsored Display and Amazon DSP, for a brand or an agency running Amazon and Walmart, is a different product from ours and we are not going to claim we cover it. SelfPub Go does one narrower thing: Amazon Ads for KDP titles, scored against the royalty and the KENP page reads in your own reports.
Why does SelfPub Go count page reads that no ad touched?
Because they are your money. Perpetua's documented KENP figures are ad-attributed by its own definition — “The estimated number of pages read by Kindle Unlimited customers attributed to your ads.” SelfPub Go starts from the KDP royalty report instead, so the KENP on screen is the month's page reads, ads or no ads, and advertising spend is set against the whole earnings line rather than the slice attribution assigned to it.
What could you not verify about Perpetua?
Several things, and they stay marked unknown rather than guessed. Whether Perpetua onboards KDP accounts today. What an individual author would actually pay, given that the published tiers start at $695 a month as of August 2026 and no author tier is listed. Whether those three KDP metrics render in the 2026 product at all — we have had no trial and no hands-on access. Which marketplaces their KDP metrics cover. Whether a trial exists at all: their own pricing page is silent, and Capterra's listing marks Free Trial and Free Version as “Not available” (checked August 2026), which is a catalog's statement rather than the vendor's. If any of this is wrong, tell us and we will correct it.
SourcePerpetua help — How to fully disconnect an integrator (December 2023)Perpetua help — Account Connection Guide (updated 6 February 2026)Perpetua — PricingCapterra — Perpetua pricing listingchecked 21 August 2026
Facts checked August 2026
Every statement about Perpetua on this page comes from Perpetua’s own website or help center, quoted or closely paraphrased, and links to the page it came from. All of it was read on 21 August 2026. Where their documentation says nothing about something, this page says that instead of concluding the thing is missing — in particular, we make no claim in either direction about whether Perpetua onboards KDP accounts today.
- Perpetua — homepage
- Perpetua — Amazon advertising software
- Perpetua — Pricing
- Perpetua blog — Introducing KENP metrics for KDP authors (3 March 2021)
- Perpetua help — Amazon KDP: what is ACOR? (updated 31 October 2024)
- Perpetua help — Why KENP Read and KENP Royalties are estimated metrics (28 May 2021)
- Perpetua help — Account Connection Guide (updated 6 February 2026)
- Perpetua help — Account Connection collection
- Perpetua help — [Sellers] How do I connect my Amazon account? (updated 31 March 2026)
- Perpetua help — How to access Stream (updated 17 February 2026)
- Perpetua help — How to fully disconnect an integrator (December 2023)
- Flywheel Digital — Retail media
- Omnicom — acquisition of Flywheel Digital (30 October 2023)
- Capterra — Perpetua pricing listing
Perpetua is not affiliated with SelfPub Go, and nothing on this page is endorsed by or written with Perpetua. Product names, trademarks and quotations belong to their owners and are used here for identification and comparison. The Flywheel and Omnicom detail above is attributed to the sources listed; the Omnicom releases do not name Perpetua.