What is KDP, KDP Select, and Kindle Unlimited?
Let’s start at the beginning.
What is KDP?
KDP (Kindle Direct Publishing) is Amazon’s self-publishing platform. It allows authors to publish and manage eBooks, paperbacks, and hardcover books directly on Amazon.
Most Pubby authors publish through KDP.
Website: https://kdp.amazon.com
What is KDP Select?
KDP Select is an optional 90-day enrollment program for Kindle eBooks.
When enrolled:
Your eBook is included in the Kindle Unlimited (KU) catalog
It becomes available to Kindle Unlimited subscribers
Amazon requires exclusivity for the eBook during the enrollment period
Only eBooks published through KDP can enroll in KDP Select.
What is Kindle Unlimited (KU)?
Kindle Unlimited (KU) is Amazon’s subscription reading service. Readers pay a monthly fee to access a large catalog of eBooks.
Books enrolled in KDP Select are included in Kindle Unlimited.
Books in KU earn royalties based on pages read by subscribers.
What are Kindle Unlimited (KU) reviews on Pubby?
If your book is available in Kindle Unlimited, you can request KU review assignments on Pubby.
Pubby reviewers access your book through their Kindle Unlimited subscription and read it directly on Amazon’s platform.
Enrolling in KDP Select
To enroll your book:
Go to your KDP Bookshelf
Find your Kindle eBook
Click the ellipsis button (…) under Kindle eBook Actions
Select Enroll in KDP Select
Confirm enrollment
You can also enroll via the Marketing page in KDP.
Important: KDP Select exclusivity
Your eBook must remain exclusive to Amazon for the full 90-day enrollment period.
During this time, you should only request KU or Verified Purchase (VP) reviews on Pubby.
Can I use Pubby if my book is enrolled in KDP Select?
Yes.
If your book is enrolled in KDP Select, you can still use Pubby.
You should use:
Kindle Unlimited (KU) reviews
Verified Purchase (VP) reviews
Do not use Standard reviews while enrolled in KDP Select, since Standard requires delivering a manuscript file outside Amazon, which may conflict with exclusivity requirements.
Important update: Standard review availability
Standard review assignments may be limited due to Amazon’s review pacing restrictions.
Amazon now limits “free access” style reviews to approximately 5 per week per reviewer, which can affect availability and speed of Standard assignments.
Because of this:
Standard reviews may be less available or slower than KU or VP
KU and VP assignments often provide more consistent activity
Which Pubby review types are most popular?
All review types are used, but behavior varies:
Standard reviews: widely used, but affected by Amazon’s weekly limits
Kindle Unlimited (KU): popular with KU readers and consistent engagement
Verified Purchase (VP): strong demand due to higher snap value
We recommend using a mix of KU and VP when possible.
Questions?
Please contact support@pubby.co with any questions.