SellerKit
As described:StopNarrowed:NarrowNo as described. Go, small, as a KDP backlist pricing and promotions extension.
self-publishing · ~$20 a month per paying account · last reviewed (next review by 29 Dec 2026) · 29 cited sources
A Chrome extension inside the KDP Bookshelf for publishers with 20+ titles: bulk price and royalty edits, timed promotions and a monthly backlist check, triggered by KDP widening its 70% royalty band in July 2026
Odds of reaching each MRR level by month 24
| MRR by month 24 | ~15 hrs/week | Full-time |
|---|---|---|
| $1k | Reaching $1k MRR by month 24 at about 15 hours a week: ≈ 40 in 100 (40%, judgment estimate). | Reaching $1k MRR by month 24 at full-time: ≈ 55 in 100 (55%, judgment estimate). |
| $3k | Reaching $3k MRR by month 24 at about 15 hours a week: ≈ 22 in 100 (22%, judgment estimate). | Reaching $3k MRR by month 24 at full-time: ≈ 33 in 100 (33%, judgment estimate). |
| $5k | Reaching $5k MRR by month 24 at about 15 hours a week: ≈ 14 in 100 (14%, judgment estimate). | Reaching $5k MRR by month 24 at full-time: ≈ 22 in 100 (22%, judgment estimate). |
| $10k | Reaching $10k MRR by month 24 at about 15 hours a week: ≈ 6 in 100 (6%, judgment estimate). | Reaching $10k MRR by month 24 at full-time: ≈ 11 in 100 (11%, judgment estimate). |
| $20k | Reaching $20k MRR by month 24 at about 15 hours a week: ≈ 2 in 100 (2%, judgment estimate). | Reaching $20k MRR by month 24 at full-time: ≈ 4 in 100 (4%, judgment estimate). |
| $50k | Reaching $50k MRR by month 24 at about 15 hours a week: < 1 in 100 (<1%, judgment estimate). | Reaching $50k MRR by month 24 at full-time: ≈ 1 in 100 (1%, judgment estimate). |
For context: across 10,150 products listing verified revenue on TrustMRR, the median makes about $30 a month and about 5% make more than $8k (analysis, Sept 2026). The odds above assume the founder conditions below are met and the narrowed version is built, so they sit well above that all-comers rate. Why.
How many months at the plan’s pace
At $20/month per customer and 5% monthly churn, adding the customers the plan needs for its month-24 checkpoint. Change any of it in the what-if model.
| MRR | ~15 hrs/week | Full-time |
|---|---|---|
| $1k | 5 mo | 3 mo |
| $3k | 19 mo | 9 mo |
| $5k | not reached | 18 mo |
| $10k | not reached | not reached |
| $20k | not reached | not reached |
| $50k | not reached | not reached |
This works only if you…
1. You can build and maintain an MV3 extension yourself(missing it: odds × 0.65)
TypeScript, content scripts, DOM selectors that survive UI changes, and a daily breakage check. If you hire the build, every KDP page change becomes a paid emergency.
2. Access to 20 publishers with 20+ titles before building(missing it: odds × 0.65)
Ideally you publish on KDP yourself, with several titles, so you have a real Bookshelf to test on and credibility in author groups.
3. A 24-hour fix promise for breakages, for 24 months(missing it: odds × 0.65)
When KDP changes a page, the extension breaks for every customer at once. The fix has to ship within a day, every time, whatever your hours per week available.
Evidence ledger
19 research findings: 12 sourced, 6 inferred, 1 unproven, 0 not rated. Tags come from the analyst's own confidence label; how tags work.
- R1.1 Merch Wizard and KDP WizardSourced
- R1.2 Merch Wizard pricing in 2019Inferred
- R1.3 Easy FoldersInferred
- R1.4 Authors pay for KDP-adjacent toolsSourced
- R1.5 No verified base rateSourced
- R2.1 Amazon Business Solutions Agreement: Agent Policy, effective 4 Mar 2026Inferred
- R2.2 KDP Terms and ConditionsSourced
- R2.3 Etsy API termsInferred
Sources
29 cited sources
- Starter Story: Rick Blyth (starterstory.com)
- Rob Cubbon: Tools, Apps and Extensions for Merch by Amazon (robcubbon.com)
- Indie Hackers post (404 on 30 Sept 2026) (indiehackers.com)
- Chrome Web Store: Easy Folders (chromewebstore.google.com)
- getbookreport.com (getbookreport.com)
- publisherchamp.com (publisherchamp.com)
- DAM Law Firm (damlawfirm.com)
- Digital Applied, 15 Mar 2026 (digitalapplied.com)
- KDP Terms and Conditions (kdp.amazon.com)
- Etsy API Terms of Use (etsy.com)
- Chrome Web Store program policies (developer.chrome.com)
- Chrome: MV2 deprecation timeline (developer.chrome.com)
- ExtensionPay (extensionpay.com)
- KDP: Price Your Book (kdp.amazon.com)
- KDP: eBook List Price Requirements (kdp.amazon.com)
- Written Word Media (writtenwordmedia.com)
- Built Written, 31 Jul 2026, updated 10 Sep 2026 (builtwritten.com)
- Vappingo: KDP sales analytics tools (vappingo.com)
- Chrome Web Store (chromewebstore.google.com)
- MerchGhost (merchghost.com)
- Merch Titans (merchtitans.com)
- Amazon Sellers Attorney (amazonsellers.attorney)
- Vela (getvela.com)
- Evlista (evlista.com)
- Sale Samurai (salesamurai.io)
- EverBee (everbee.io)
- Meesho Supplier Analytics (chromewebstore.google.com)
- Meesho Seller Lens (chromewebstore.google.com)
- TrackEcom (chromewebstore.google.com)