Is KDSPY (Kindle Spy) An Essential Tool For Your Kindle Publishing Business?

KDSPY v5 Logo

Anyone who has been in the self-publishing business long enough knows the pain of performing niche research. It’s the most time consuming part of creating a book, but it’s necessary if you want to write a bestseller.

You have to ensure that there is enough demand for your idea to justify the investment of time and money required to write and publish a book about it. The book category you end up choosing will have a big impact on whether or not your book sells. Simple choices and tweaks can result in hundreds of additional visitors, which equates to more sales.

Fortunately, there are tools you can use to automate the keyword and category research process. One such tool is KDSPY (formerly known as Kindle Spy) by Kindle publisher Wesley Atkins. He’s also the creator of KDROI, which we’ve reviewed here.

This post is an in-depth review of KDSPY v5 and its features.

Table of Contents

KDSPY Review

What is it?

KDSPY v5 is a browser extension that enables Kindle publishers to reverse engineer the bestseller categories in the Amazon Kindle marketplace and discover hot niche opportunities. It will help you:

  • Find the right keywords for your title and subtitle so that the right readers find your book.
  • Give you an indication of whether there is demand for your book idea before you start writing.
  • Discover the competitiveness of certain niches and whether they are worth your time.
  • Spy on competitors in your chosen niche and replicate their success.

KDSPY v5 retrieves the sales data of the top 20–100 bestsellers for a particular keyword or category and shows you at a glance whether or not a niche is profitable. Research which usually takes publishers hours can be cut down to minutes using this tool.

KDSPY Features

Clicking on the KDSPY browser extension will redirect you to the Amazon marketplace for Kindle books. Below are some of the key features of the software.

  1. Bestseller Rankings

KDSPY’s bestseller ranking tool is one of its most useful features. It shows stats like page numbers, price, estimated sales, monthly revenue, reviews, and sales rank. This feature works on any Kindle book category.

Bestseller Rankings

The above screenshot shows stats for the top 20 bestsellers in the paleo diet category. You can expand the list to include information for up to 100 books. As you can see, The Autoimmune Fix: How to Stop the Hidden Damage That Keeps You Sick, Fat, and Tired Before It Turns Into Disease by Tom O’Bryan currently holds the top spot. Its sales rank is 118 and it has an estimated monthly revenue of $14,179.

KDSPY v5 added a notification that tells you how many books you need to sell to reach No. 1 and No. 20 in the bestseller list. You need to sell 945 books in 24 hours to reach No. 1 in the paleo diet category and just eight books to reach No. 20.


how many books you need to sell


KDSPY uses a traffic light system to give users an overview of the profit potential of a particular keyword. The traffic lights show three metrics: Popularity, Potential, and Competition. They can be red, yellow, or green.


traffic light example


The paleo diet category has good potential with one yellow and two green lights. If all the lights are green then publishing a book in that category is a good idea. But if the lights are all red, then there’s probably too much competition and little profit potential. The algorithm is not 100% accurate, but it should give you a good indication of what to expect.

All the data KDSPY pulls can be exported to an excel file.

  1. Book Tracking Over 30 Days

Clicking on the ‘T’ in the second column opens a rank tracking tool lets you follow the rank of a book over a month. The ‘S’ and ‘C’ are search tools. When you click on the ‘S’ , KDSPY will use Google to search for the book title. The search results can give you a rough idea of the main traffic sources its publisher is using. Clicking the ‘C’ performs a Google image search of the book cover, giving you more potential traffic sources.


book tracking demo


book tracking demo 2


KDSPY will start collecting data once you enable sales rank tracking. You have to open your browser every day if you want KDSPY to collect more data. It can track a book for up to 30 days. You can quickly monitor the books you track or stop tracking by using the ‘Rank Tracking’ link at the top right of the KDSPY window.

The below screenshot shows data collected over five days from tracking The Plant Paradox: The Hidden Dangers in “Healthy” Foods That Cause Disease and Weight Gain by Steven R. Gundry.


5 day data


  1. Spy on Self-Published Authors

KDSPY can analyze an author’s page and show you what other books they’ve published, the sales rank for those books, average monthly revenue, average number of reviews, and average price. For example, the No. 1 bestseller in the meditation category is a book called Aware: The Science and Practice of Presence by Daniel Siegel.


author page analysis


When you use KDSPY v5 on Daniel Siegel’s author page, you can see he has published 13 books and has an average sales rank of 692,930 and an estimated total monthly revenue of $1,463, which isn’t too bad. When you sort his sales rank by ascending order, you can see that his bestselling book is Mind: A Journey to the Heart of Being Human.


author page


bestselling book


  1. Search Tool

Authors can use the search tool to search for keywords and get keyword suggestions along with a traffic light signal that estimates the competitiveness of each suggestion. The screenshot below shows a search for the keyword ‘meditation’.


search tool


KDSPY v5 now includes an option to pull A-Z search results, which automatically inputs your seed keyword into Amazon search followed by the letter ‘a’, ‘b’, ‘c’, and so on, to get Amazon’s suggestions for keyword phrases.

The search results also include the number of competitors for a keyword phrase and a link to its estimated average monthly revenue. When you choose the ‘Analyze’ option, the software will show you the bestsellers that rank for that keyword.


analyze option


As you can see above, the keyword phrase: “meditations marcus aurelius” doesn’t have a lot of competition, but it’s also unpopular and has little profit potential. The ‘Keyword Analysis’ option at the top can show you a more detailed breakdown for books that use that keyword.


Keyword Analysis


The KWT value checks if the keyword is present in the title and the KWD value checks whether the keyword is present in the description. Books that don’t have the keyword phrase in the title or description should be easier to compete with.

  1. Word Cloud

The word cloud analyzes the titles of the bestsellers in a particular niche and reveals which words are most frequently used in their titles. It’s handy for discovering what words will help in your book rank well.


Word Cloud


The above screenshot shows the most popular words used by the top 20 bestsellers in the meditation category. The top five words are: mindfulness, meditation, how, life, and your. These are the hottest words for titles in this category, which means you should try to use them when coming up with a catchy title for your book.

New Features in KDSPY v5

The newest version of KDSPY (v5) adds the following improvements:

  • Book results include paperback and hardcover books – This was one of the most requested features by users. Even though KDSPY is still primarily a Kindle research tool, book results will now include paperback and hardcover books.
  • Book tracking covers Kindle, paperback, and hardcover books – The book tracking feature will include paperback and hardcover books. The tracking page will have tabs for Kindle, hardcover, and paperback books.
  • Author pages now include data for Kindle, paperback, and hardcover books – Author pages will feature tabs that group an author’s published books as Kindle, paperback, or hardcover books.
  • New estimated daily sales requirement algorithm – KDSPY v5 includes a new algorithm that tells you how many books you need to sell in 24 hours to rank No. 1 and No. 20 in any book category.
  • Improved accuracy on estimated monthly sales algorithm – The algorithm KDSPY used to calculate estimated monthly was good, but it wasn’t 100% reliable. KDSPY v5 improves the accuracy of the algorithm to give you better results.
  • Extensive (A-Z) search suggestions – The keyword search tool now includes an option to pull A-Z search results. Search results also include the number of competitors for a keyword phrase and a link to its estimated average monthly revenue.
  • New look and feel – KDSPY v5 has a new look with tabbed formating for book results. You can sort your results by Kindle books or paperback/hardcover books. More variations of books (Audible books, etc.) may be added in the future. 

How Much Does KDSPY Cost?

KDSPY has sold in the past for $97, but it’s currently available for a discounted one-time payment of $47. There is no subscription or any hidden fees. The price includes free lifetime updates of the software and a 60-day satisfaction guarantee. You can buy a copy of the latest software here.

KDSPY Installation

The KDSPY browser extension works on Google Chrome and Firefox. The Chrome version can be downloaded directly from the Chrome Web Store.

To install the Firefox version, you have to download the latest version of the software directly from the official website (when you have an account). Drag and drop the file into your Firefox browser to install it. Unfortunately, the Firefox extension doesn’t automatically receive updates, so you’ll have to remove and reinstall it whenever a new update is released.

Note: The KDSPY browser extension won’t work until you buy the software and log in with your username and password. There are no free trials.


  • Gets regular updates – KDSPY is regularly updated with new features.
  • Great price – A one-time payment of $47 is an unbeatable price for a tool with so many useful features.
  • Easy-to-use browser extension – KDSPY is intuitive to use and can quickly be installed on Chrome and Firefox browsers.
  • Book tracking – You can keep an eye on as many Kindle books as you like using the book tracking feature and collect performance data over 30 days.
  • Supports multiple Kindle stores – KDSPY is not limited to data from the U.S. Kindle marketplace. It supports eight other country-specific Kindle stores: UK, Canada, Germany, Italy, Spain, India, France, and Japan.


  • No automatic updates for Firefox – Firefox users must manually remove and reinstall the software whenever a new major update is released.
  • Doesn’t show Amazon demand data – KDSPY doesn’t display the estimated monthly Amazon searches for keywords like other Kindle publishing tools.
  • No support for Safari and other browsers – KDSPY doesn’t have any plans to release an extension for Safari, Microsoft Edge, and other browsers.

Final Thoughts

Book market research can help you make better decisions when writing your book, choosing a title, designing a cover, writing the description, and marketing the final product. Along with the similar but more expensive Publisher Rocket, KDSPY takes the work out of the process by helping you to quickly find the right category for your book. You won’t have to waste valuable time manually going through dozens of niches to find the right one for your book.

Having such a big competitive advantage over other authors can feel like cheating, but it really just means you have a better understanding of the market. Gaining that knowledge for just $47 is a steal, and to top it off, the software gets free updates forever. We think it’s a worthy addition to your Kindle publishing tool belt and wholeheartedly recommend it.

Download Package

Click Here to Download KDSPY (v5)



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