KD Spy vs Publisher Rocket vs Kindle Samurai [2020]

Welcome to the showdown between the big beasts of the world of Kindle keyword software!

In this article, we will delve deep into the tools which claim to turbocharge your Kindle publication efforts through strategic keyword research and competitive analysis.

If you’ve ever had the experience of investing your hard earned cash into a product or service which failed to live up to the hype, you know how badly it sucks. It can even cause us to become cynical, doubtful that any products are trustworthy and live up to the hype.

Thankfully, help is at hand. We have taken the time to test, explore and review the three big players within the world of Kindle keyword software: KD Spy, Kindle Samurai and Publisher Rocket. So, read on to discover –

  • How Kindle Keyword Software Can Help You
  • Kindle Keyword Software Deals & Guarantees
  • KD Spy VS Kindle Samurai VS Publisher Rocket –  Features Compared
  • The NerdyBookGirl Pick For Best Overall Choice

By the end of this article, you’ll have a full understanding of how to make the most of your chosen Kindle keyword software, and which is right for your needs.

Benefits Of Kindle Keyword Software

Perhaps you’re sitting there thinking ‘why should I even care about this software?’. If so, I totally understand. It’s not immediately obvious why you would want to invest in something like this. In a nutshell, using keyword software can help you in the following ways –

  • Using carefully researched keywords in your title and subtitle can help the right readers find your book
  • You can write a book safe in the knowledge that there is actual demand for your idea before you get started
  • You can see how competitive certain niches are and whether they are worth your time
  • You can look for beatable competitor books which you can gain a solid competitive advantage over

Some people have moral qualms over keyword software, seeing it as ‘gaming the system’ or some other form of tomfoolery. In actual fact, there is no way to ‘game the system’. Do you really think Amazon would allow it? They have strict policies over keyword usage. If you violate them, your book will get taken down – simple as that.

Therefore, using keyword software is very much playing by the rules, and is simply a way of giving your book a helping hand.

Kindle Keyword Software Deals & Guarantees

Before we go deep into the features offered by each of our analyzed keyword software, I want you to feel safe in the knowledge that you can spend money without any risk. Therefore, let’s take a look at the guarantees offered by each software.

KD Spy – 60 Day No Questions Asked Money Back Guarantee

Kindle Samurai – 30 Day Conditional Guarantee (will only refund you if they can’t fix an error within 72 hours)

Publisher Rocket – 30 Day No Questions Asked Money Back Guarantee

As you can see, you can try KD Spy and Publisher Rocket with complete confidence in getting a refund if it’s not to your liking.

You need to be a bit more cautious with Kindle Samurai as they only offer refunds in the case of errors that can’t be fixed within 72 hours. This is a serious disadvantage over KD Spy and Publisher Rocket.

KD SpyKDP Rocket Kindle Samurai
Guaranteed Refund Period 6030None
Standalone SoftwareNoYesYes
Windows Compatible YesYesYes
Mac Compatible YesYes3rd Paty Only
Shows Google Demand Data
Shows Amazon Demand DataNoYesNo
Level of Keyword Analysis BasicDetailedBasic
Level of Competition AnalysisBasic DetailedBasic
See Book Cover In AppNoYesNo
Read Reviews In AppNoYesNo

Kindle Keyword Software Showdown – Idea Research Comparison

Let’s take a closer look at one of the main purposes of Kindle keyword software – researching your book idea. We’ll explain the basic principle behind the process, before looking at each of our three contenders’ capabilities in turn.

The basic principle behind finding a good book idea is to ensure that there is demand for your idea in order to justify the investment of time required to write and publish it. This requires taking a quantified, analytical approach, in order to judge whether the amount of people looking for your idea justifies pursuing it further.

Now let’s take a look at each Kindle keyword software’s idea research capabilities.


KD Spy is more heavily focused on finding Kindle categories than it is on researching keyword ideas. However, it claims to be useful in that area as well, so let’s see exactly what it offers.

One way in which you can use KD Spy to research ideas is to check out its ‘word cloud’ feature which shows you the words used in titles of books selling well within a certain category. This isn’t especially useful as you just end up with a list of really obvious words that are heavily derivative and are unlikely to represent a new, original, book idea. It’s also next to useless for fiction, because who wants to base their title off a mashup of other fiction book titles?

The other main way to use KD Spy to research an idea is to conduct a search with a seed keyword. The software then uses what seems to be Amazon’s autosuggest function to generate a list of ideas based on what you’ve entered. You are given a red, yellow or green light for each, with green being the easiest to compete in, and red being the hardest. This is a bit basic as there is no easy way to differentiate between two ideas with the same color rating.

You can then go into each idea individually in order to look at more data on it, but this does not make it easy to compare multiple ideas at once, and KD Spy does not attempt to show you the number of searches for an idea on Google or on Amazon.

Overall, using KD Spy for the purposes of finding a good keyword based idea is not ideal. The software is more geared towards finding categories and therefore isn’t the best choice for idea research, as it lacks too many needed features, such as Google and Amazon search volume.

Kindle Samurai Idea Research

Kindle Samurai makes no secret of the fact that its main purpose is keyword research. It’s more limited in scope in that sense than KD Spy and Publisher Rocket. So let’s see exactly what it’s made of and how it can be used to research a book idea.

With Kindle Samurai, you can enter an idea and it will use a mixture of Google search data and Amazon autosuggest to generate a list of keywords. The interface for generating keywords is a little bit clunky and confusing, especially in comparison with KD Spy and Publisher Rocket. In general, Kindle Samurai is very much a no-frills option on the visual presentation side of things. It’s clear enough, but definitely not pretty. Think of using a spreadsheet and you have a good idea of what the user experience resembles.

For each keyword analyzed, you can see data such as the number of Google searches, the number of results for each keyword, the average price for books ranking in that keyword, and whether Samurai thinks the keyword is ‘bad’, ‘difficult’ or ‘excellent’. This is again a basic level of analysis, similar to the traffic light system used by KD Spy, which is not that useful. You have to do a lot of work to meaningfully figure out the difference between two keywords rated as ‘excellent’, for example.

Overall, Kindle Samurai is better for research than KD Spy, but has a lot of disadvantages. It’s also really ugly, so if you don’t enjoy staring at plain looking spreadsheets, this isn’t the software for you.


Publisher Rocket has made significant improvements to its functionality since launching. Let’s take a look at the process of using Publisher Rocket to research a book idea through the use of keywords.

Publisher Rocket has a much more intuitive layout than the other two keyword tools mentioned in this article – you can easily click a big, bright ‘keyword search’ button on its home screen. This attractive presentation is nicer than that found in KDSpy and a LOT nicer than Samurai, but what about the functionality? After all, a pretty package is useless if it fails to deliver core functionality.

To research idea keywords with Publisher Rocket, you simply enter a seed keyword, and Rocket gives you a list of possible ideas, based on Google as well as Amazon search data.

The absolutely killer feature which gives Publisher Rocket an advantage over KD Spy and Kindle Samurai is its presentation of both Google search volume for an idea, and estimated Amazon search volume as well. The estimated Amazon search volume is not found anywhere else – this alone makes Publisher Rocket seriously worthy of your attention. After all, knowing how many people are searching for a keyword on Amazon itself equals some very useful, very actionable competitive intelligence.

The final way in which Publisher Rocket has improved upon its older rivals is by offering a score between 1-99 showing the difficulty of competing for any given keyword. This is much better than the overly simplistic analysis found in KD Spy and Kindle Samurai. After all, it’s much easier to instantly know the difference between ideas with scores of 20 and 30 than it is to trawl through the data related to two ideas marked ‘green’ or ‘excellent’.

Overall, Publisher Rocket offers a higher level of functionality than KD Spy and Kindle Samurai, and is more aesthetically pleasing and intuitive.

Kindle Keyword Software Showdown – Idea Research Verdicts

Best – Publisher Rocket
Runner Up – Kindle Samurai
Worst – KD Spy

KD Spy comes in last place due to its extensive limitations as an idea research tool. Kindle Samurai offers a good basic level of functionality, while Publisher Rocket is the clear winner due to several unique features not found elsewhere.

Kindle Keyword Software Showdown – Competitor Analysis Comparison

Finding a good idea is only one half of the cake – it’s also essential to determine what the competition is like for each idea, and to identify areas of potential competitive advantage, in order to ensure your book is able to convert search volume into sales volume.

In this section of our showdown, we’ll take a look at the competitor analysis capabilities of our three pieces of Kindle keyword software, before ranking them on this aspect of the book research process.[/vc_column_text]


If KD Spy is somewhat lacking as an idea research tool, it is a lot better as a competitor analysis software. This is somewhat frustrating as having one without the other is far from ideal.

To look at the competition on KD Spy, you need to first enter a keyword, in order to generate a results page. This is fine if you have the right keyword already, but as stated, finding it through KD Spy alone is less than ideal. On the results page, you can see the basic data needed to analyze the competition, such as the price of each competing book, the number of reviews, the average review score, the estimated sales etc. No complaints about the data here. However, the presentation is a little hard on the eyes, albeit not as much as Kindle Samurai.

It’s worth emphasizing once more that KD Spy is a browser extension, so you are required to have your browser open at all times while using Spy. This obviously leaves you vulnerable to the potential disruption of a browser crash ending your research session prematurely. This isn’t a major downside, however it’s something to be aware of.

One cool thing about KD Spy is the ability to track the rank of a book over a period of time – however this is only really useful if there is a specific title you are going up against. One downside to KD Spy is it does not allow you to see the book cover in the browser extension, only on the Amazon page itself. It also does not allow you to read the reviews for any given title in the extension.

Overall, the data provided with which to analyze the competition is decent, but the lack of a good idea research capability means that you’ll probably have to validate your initial idea elsewhere.


Some people think that you can’t use Kindle Samurai to analyze competition. They’re wrong. You can – but probably shouldn’t!

For any given keyword, Kindle Samurai will show you the data for the front page for that keyword only. This is a serious limitation in comparison to KD Spy and Publisher Rocket. It also presents the data in its trademark ‘ugly spreadsheet’ aesthetic. The data presented for each title is a little lacking – it offers the basics like rank, reviews, pages etc. but doesn’t calculate earnings for you, meaning you have to do math for each and every title (who wants that?).

You also can’t see the actual reviews for each book, only the average score, and you can’t see the book cover either. Seeing as the book cover is an absolutely essential aspect of competitive analysis, and reading the reviews is a must to judge areas on which to gain a competitive advantage, there is absolutely no point whatsoever in using Kindle Samurai as your competition research tool.

Overall, this is not good enough. The number of results shown is too few and the data presented is lacking. Kindle Samurai is not a good choice here.


We’ve established that Publisher Rocket is the best choice for researching a book idea. However, can it go 2 for 2 and clean up in the competitor research showdown?

You can research a competitor in one of two ways on Rocket. Either use one of your ‘keyword search’ results, and open it in a new ‘competition search’ tab, or directly search for a keyword to analyze the competition on.

One cool thing about Rocket is the way in which you can easily go back and forth between the ‘keyword search’ and ‘competition search’ tabs. The presentation is also a lot more easy on the eye than KD Spy or Kindle Samurai.

So, what about the functionality and data offered?

Publisher Rocket offers all of the standard data, such as the price of the book, the number of reviews, the average review score etc. However, it also offers aspects not found in either competing software.

Some of the unique aspects to Publisher Rocket’s competitor research process include its calculation of both daily and monthly earnings, and the ability to see a full list of reviews as well as the book cover within the actual software itself. This is awesome. You can also see whether the reviews are verified or not – something not offered by the other Kindle keyword software, despite the fact verified reviews have a lot more weight on Amazon than unverified reviews.

This detailed, rich, qualitative and quantitative mix of competitive data, coupled with the seamless integration with the ‘idea search’, means Publisher Rocket is a really powerful book research solution.

Overall, this is a fantastic function of Publisher Rocket. It is impressive due to its presentation, unique data offered, and seamless integration with Rocket’s keyword search.

Kindle Keyword Software Showdown – Competitor Research Verdicts

Best – Publisher Rocket
Runner Up – KD Spy
Worst – Kindle Samurai

Publisher Rocket, once again, is a clear winner here. It offers better data presented in a nicer way. KD Spy is good, but the lack of a good idea search capability makes its competitor research a lot less useful than it could be. Kindle Samurai is simply not good enough when compared with the other two options.

Kindle Keyword Software Showdown – Final Verdicts

Now that we’ve taken a detailed look at the capabilities of all three software packages, let’s sum up the pros and cons of each, and see who might be the ideal customer for each option.

Kindle Keyword Software Showdown – The Winner

So, by now, a clear winner has emerged – Publisher Rocket.

I truly feel that this is the best choice out there for both idea research and competition research, and I’m confident if you try it for yourself you will agree with me.

I like the fact that Publisher Rocket has been created by a trusted, known name in the self-publishing community – Dave Chesson of Kindlepreneur.

I feel that the $97 price can easily be recouped through the profitable book ideas you’ll find with Publisher Rocket. I also feel safe making this my top pick as the no questions asked money back guarantee means you can give it a go for yourself without worry.

You can read my in-depth exploration of Publisher Rocket here.

So, there you have it. A guide to the world of Kindle keyword software.

Now go and rock it with Rocket, and send your book research into the stratosphere (what do you mean my puns are awful?!?).


Good Points

Good for tracking a particular book
Decent competitor research functionality
Good for exploring categories

Bad Points

Only available as a browser extension
Subpar as an idea research tool
Averagely attractive layout

Is It Right For Me?

If your main focus is on Kindle categories, KD Spy could be worth checking out as a budget option. If you want to research your book idea, or analyze the competition, there are better options.


Good Points

Decent basic keyword research tool

Bad Points

No money back guarantee (only a conditional, obtuse promise to fix issues)
Spammy sales tactics (a fake discount countdown timer on the sales page)
Horrible presentation
Very lacking competition research capabilities

Is It Right For Me?

If you want to spend the least amount of money possible, and don’t mind the lack of a refund guarantee, you might want to check out Kindle Samurai. However, if you are in anyway serious about book idea research, you’ll eventually want to buy something better. So why not cut the wait time and buy something better right away?


Good Points

The highest level of functionality
The most attractive and intuitive presentation
Unique functionality in both idea and competitor research modes

Bad Points

A slightly more premium price (more than KD Spy) for an undeniably premium product

Is It Right For Me?

If you are serious about finding a book idea with real profit potential, and conducting the highest level of competitor research out there, Publisher Rocket is well worth your attention. $97 for lifetime access is excellent. This does everything KD Spy does, but better. It also does a lot more.

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