there is a story behind every book

Guide to RADAR by Jellybooks

reader analytics, data, and audience research

Discover the power of reader-centric data and analytics with Jellybooks RADAR and learn how leading international publishers have been using the service to turn manuscripts into bestsellers.

With Jellybooks RADAR publishers gain insights into what percentage of readers finish a book, how fast they read the story, if they were satisfied with their reading experience and much more. The service quantitatively measures how readers engage with books.

The key to any book’s success is to accurately match the right book with the right audience.

  • Jellybooks RADAR brings the best of modern market research to publishing at a modest and affordable cost.
  • With Jellybooks RADAR publishers can identify the core demographics and audience for a book so it is optimally positioned in the marketplace.
  • Jellybooks will find the test readers, organise the campaign and do the analysis for the publisher. All the publisher needs to do is upload the ePub file, enter the meta-data, set the campaign start-date and lean back while Jellybooks does the work.
  • Jellybooks RADAR is unique in the market and publishers will find no comparable service.
  • The company is trusted by the industry’s leading publishing groups such as Bertelsmann, Holtzbrinck, Harper Collins, Bonnier, Simon & Schuster, Egmont and Atlantic Books. It has been instrumental in the success of many bestsellers in the UK, US and Europe.

The service is easy to use, secure and a proven winner for publishers.

free sign-up

Secure your free Jellybooks RADAR campaign by signing up before 31 May 2021. Available to IPG, ALPSP, PA and BMS members, subject to available capacity and at the discretion of Jellybooks. We have reserved thirty campaigns exclusively for the first thirty IPG members who sign up by 31 March 2021.

Top Ten Benefits & Features of RADAR

1. Accurately identify the core demographics and audience for a book.
Which age group and gender does the book appeal to most? What kind of TV and Netflix shows do those readers watch? Which books are readers most likely to compare this title to?

2. Use real readers to identify the right categories for a book
Which categories does the book fit into? Is the appeal genre-specific or does the book attract a wider audience? Does the book have cross-over potential, such as YA to adult? What attributes and keywords do readers use for the book?

3. Establish comparables across books, TV shows and movies
A cross-media analysis can demonstrate how best to reach the book’s audience. Discover fans of specific Netflix series, TV shows or movie franchises that your book appeals to, as well as how likely they are to finish and recommend a book.

4. Use A|B testing to test a range of covers.
Use readers who have actually completed the book to feedback on potential covers, either with a side-by-side test (users can compare) or with a blind A/B test where test readers are not aware that there engagement is being measured relative to the cover they are being shown. RADAR allows for decision making not made by readers as to whether they like a cover or not, but based on actual engagement. This includes completion rate, satisfaction index, recommendation factor, and how well the cover matches the content using a cover-match-factor).

5. Ensure your title information is correctly positioned
Test and identify the correct genre description, shout line, book description and other key elements in order to correctly position a book in the market. Reader analytics also provides real-time data to see how different messages perform and provides deep insights into users’ psychology.

6. Use data to reach a consensus for the publishing direction
Gather reader engagement data to reach internal consensus. Some books generate many questions and intense debate leading to uncertainty, doubt and mistaken decisions. Data gets people on the same page.

7. Ensure sure your marketing is spent effectively
Use audience data generated by RADAR to help decide the level of online advertising and overall budget to allocate to a book. Ensure your marketing budget is being spent where it has the most impact on titles with the widest sales potential.

8. Identify why a book didn’t perform to expectations
Use our RADAR focus groups to find out why a book did not perform as expected. Was it down to copy, category, packaging or another factor? Data helps define new directions and correct mistakes prior to launching a paperback or new edition.

9. Use Reader engagement data to demonstrate audience and appeal
Reader engagement data can be used to illustrate audience size and potential to retailers. Demonstrate that a high percentage of those who read a title would recommend it for instance.

10. How likely are readers to buy more books from your author?
Measure the strength of an author’s platform to see how strongly engaged buyers are. For example, a debut author sold well but was it a novelty/newcomer effect?

free sign-up

Free use until 31 May 2021 courtesy of Arts Council England. The offer is subject to available capacity and suitability of book.

How Jellybooks RADAR works

Who gets invited?

Using virtual focus groups, Jellybooks invite test readers from its panel via email. In addition we use social media to reach out to additional readers based on what kind of reader the publisher wishes to test a book with.


Publisher supplies Jellybooks with an ePub 3 file, a high-resolution cover image, a book description and some basic meta-data (author, publication date, ISBN).

There is also the option for publishers to invite their own test readers or audiences in addition or instead of the Jellybooks test reading panel.

What do readers receive?

Participants are paid no monetary compensation. Our experience of having conducted hundreds of test reading campaigns over the past five years shows that receiving a free eBook and the knowledge that somebody is paying attention to them is sufficient reward for participants.

Registered test readers receive eBooks that have been specially modified by Jellybooks to record their reading and engagement data. Test readers can choose from a range of reading apps for smartphones, tablets, laptops and PCs including Apple Books, as well as the Jellybooks Cloud reader. E-Ink based devices such as Kindle, Nook, Tolino and Kobo are currently not supported, because these device support only the ePub2 format and no JavaScript support which is required for data collection.

Data is only transmitted when readers click on the purple “sync reading stream” button at the end of each chapter. The system is essentially double opt-in and participants explicitly consent to their reading data being collected. Participants also have the ability to view visualisations of their own reading data online and access all the data that Jellybooks has collected and holds on them.

The eBooks distributed by Jellybooks are not encrypted, but contain a range of “social DRM” features including visible and invisible watermarks and other tracking and identification features. In addition, participants know that they are being observed during the test reading campaigns which greatly inhibits casual sharing and “piracy”.

Results and Analysis

Results are available in real time through the Jellybooks data portal, called Candy, and printable reports are available in real-time as well.

A first analysis of trends is usually possible after two weeks when first fifty to hundred readers have completed their book. The total test duration is about six to ten weeks.

All data collected is available both in pseudonymous form (reading and survey data for individuals) and in aggregated form (reading data for the entire focus group or sub-segments thereof). The platform is fully GDPR compliant.

FAQ – Frequently asked questions about the Jellybooks RADAR service

How much individual reader feedback is received?

The feedback that Jellybooks collects during a test reading campaign can sometimes provide key insights into how readers respond to a book. These comments are private (not posted or redistributed publicly) and as a result they are very frank and informative. They provide insight into what resonates with readers or annoys them, but also allows the publisher to check if the reader making the comment has actually read the book (reading data is available in pseudonymous form for individual users and can be matched to a specific user’s comments and feedback).

How do you undertake cover research?

Readers do judge a book by its cover, and Jellybooks has the data to prove it. Traditional interview techniques often fail when testing covers, because readers, having little context or commitment, judge the cover primarily on its aesthetics. In contrast, Jellybooks applies a tried and tested scientific concept: the double-blind A|B test. This allows Jellybooks to test covers without users being aware that they are being tested on the cover.

The Jellybooks cover-match factor (CMF) measures how well readers think a cover matches the content of a book. We also undertake A|B testing, where we split the focus group randomly into two sub-groups and give each sub-group a different version of the cover without readers being cognizant of this. Readers are only aware that we are collecting their reading data. They do not know about the specific variations in “packaging” (cover, title or description), which is why the test is referred to as double-blind: readers are blind to which group they belong to and the tester is blind to which readers get what version (random assignment by algorithm). This ensures that any cognitive bias is minimized during the study. As part of an A|B test, Jellybooks can also establish the pull of the cover, i.e. are readers more likely to choose the book based on its cover. This requires the test to have a choice between at least two titles: covers matter a lot when readers have to choose between books and select which book to read.

Between 500 and 800 test readers are recruited when executing an A|B test to ensure that statistically valid results can be obtained. A|B tests are best suited for testing covers that are based on very different concepts or propositions.

How do territorial restrictions work?

Territorial restrictions are based on the IP address of the user’s device. Users reading outside the designated territory see their access blocked.

free sign-up