# KDSpy

> Browser extension that overlays live sales estimates, category intelligence, and AI-powered niche insights directly on Amazon search pages — no app switching required.

Source: https://selfpublishingdirectory.com/keywords-metadata/kdspy
Website: https://kdspy.com
Category: Keywords & Metadata (https://selfpublishingdirectory.com/keywords-metadata)
Pricing: paid — $79/one-time
AI-powered: yes
Editor's pick: yes
Tags: browser-extension, sales-data, niche-research, category-analysis, competitor-research, amazon, kdp
Last verified: 2026-05-14
Best For: Quick niche and category validation before committing to write or publish
Data Source: amazon-sales-estimates
Platform: web
Tool Type: keyword-research, rank-tracker

KDSpy is a browser extension that surfaces market intelligence the moment you click its button on any Amazon search results page. Instead of copying ASINs into a separate app, you see sales estimates, revenue projections, and category competition data overlaid on Amazon itself — making it the fastest way to validate a niche idea or benchmark a competitor.

## What You Get

- **Sales & Revenue Estimates**: Monthly sales and income projections for any book in Amazon's catalog, drawn from BSR data across Kindle, paperback, and hardcover formats.
- **Category Intelligence**: Analysis of 25,000+ Amazon categories — click any category to see average sales, competition levels, and the daily sales needed to reach the top 20 or earn a #1 bestseller rank.
- **Author & Publisher Analysis**: Investigate competitor author pages to see catalog performance and pricing strategies without navigating multiple pages manually.
- **30-Day Sales Tracking**: Monitor a book's sales rank and revenue trajectory over a month — useful for tracking your own launch or watching a competitor react to price changes.
- **AI Niche Insights**: ChatGPT-powered prompts that analyze a niche's viability and surface keyword angles that manual browsing might miss.
- **International Coverage**: Research across 13 Amazon stores — US, UK, Canada, Germany, Australia, Italy, Spain, France, India, Japan, Mexico, Brazil, and Poland.

## Who It's For

- **Niche validators**: Authors testing whether a genre or topic has enough demand before writing. KDSpy's browser-based speed makes it ideal for rapid idea screening across multiple categories.
- **Category strategists**: Authors who want to identify the least-competitive subcategory where their book can realistically earn a #1 bestseller tag.
- **Budget-conscious researchers**: At $79 one-time versus Publisher Rocket's $199, KDSpy suits authors who want solid market intelligence without the premium price.

**Pricing:** One-time $79 — no subscription, no renewal. Includes a dual license for two devices, lifetime updates, and a 60-day money-back guarantee. Works on Chrome, Firefox, Edge, Opera, and Brave; Windows, Mac, Chromebook, and Linux.

## Strengths

- **No app switching**: Market data appears directly on Amazon search pages without leaving the browser — the workflow advantage over desktop apps is real.
- **Category depth**: Access to 25,000+ Amazon categories is broader than most competitors; finding the right subcategory for a bestseller ranking is easier here than anywhere else at this price.
- **One-time pricing**: Permanent access at less than half of Publisher Rocket's cost is a meaningful advantage for authors who need basic market research without advanced ad keyword tools.

## Limitations

- **No keyword search volume**: KDSpy does not show estimated monthly search volume for keywords — a critical gap compared to Publisher Rocket. You can validate category demand, but you cannot evaluate which search terms drive that demand.
- **No Amazon Ads support**: No AMS or Sponsored Products keyword research. Authors running paid advertising campaigns need Publisher Rocket or Helium 10 for that function.
- **Dated interface**: Multiple reviews from 2024–2025 note the UI looks outdated — functional, but not polished. The core research workflow is unchanged since early versions.
- **No Safari support**: macOS users who prefer Safari must switch to Chrome, Firefox, or Edge to use the extension.

## Alternatives

Publisher Rocket ($199 one-time) adds keyword search volume, competition scores, and AMS ad keywords — making it more complete for launch planning and paid advertising. Many experienced authors use both: KDSpy for quick category and sales validation during research, Publisher Rocket for keyword strategy when preparing to publish or run ads.