Publishing glossary
Every KDP, Audible and indie publishing term, in plain English.
A
- ACoS
- Advertising Cost of Sale. Total ad spend divided by sales generated by those ads. Lower is better.
- A+ Content
- Enhanced product description on Amazon: images, comparison tables and richer copy. Improves conversion.
- ARC reader
- Advance Review Copy reader. A volunteer who receives a free copy in exchange for an honest review.
- ASIN
- Amazon Standard Identification Number. The 10-character ID Amazon assigns each product, including books.
- Audible bounty
- A bonus paid by Audible to authors when a new Audible member buys their book as their first purchase.
B
- Backend keywords
- The 250-byte field in KDP where you list hidden keywords that affect ranking but are not shown to readers.
- BSR
- Best Seller Rank. Amazon's position metric across all books in a category. Lower is better; #1 is top.
C
- Comp title
- A comparable bestseller in the same subgenre. Used for market positioning, ads and queries.
- CTR
- Click-through rate. Clicks divided by impressions. A cover and title quality signal.
D
- Dark publishing
- Publishing under a pen-name with zero personal branding. Common in romance and erotica niches.
E
- EPUB
- Standard reflowable e-book format. The industry standard outside Kindle.
G
- Glossary lock
- In translation: enforcing fixed terms across an entire series. Prevents inconsistent renderings.
H
- Hot New Release
- Amazon badge given to new books gaining rank fast in a category. First 30 days only.
I
- Impressions
- How many times your book appeared in search or browse. The top of the funnel.
K
- KDP
- Kindle Direct Publishing. Amazon's self-publishing platform for ebooks and paperbacks.
- KENP
- Kindle Edition Normalized Pages. The unit Kindle Unlimited pays you for — pages read.
- KU
- Kindle Unlimited. Amazon's subscription where readers borrow your book and you earn per page read.
L
- Long tail
- Low-volume, high-intent keywords. Less competition, often better ROI.
M
- MOBI
- Legacy Kindle format, now mostly replaced by KFX and EPUB on KDP.
P
- Permafree
- A book set to free permanently as a funnel into a paid series.
R
- Read-through
- Percentage of book 1 readers who go on to buy book 2 in a series. Key indicator of series health.
- Royalty rate
- Your percentage of retail price. KDP pays 35% or 70% depending on price band and territory.
S
- Series page
- Amazon page grouping all books in a series. Improves discovery and series rank.
T
- TACoS
- Total Advertising Cost of Sale. Ad spend divided by TOTAL sales (organic + ad), not just ad sales.
W
- Wide
- Selling outside Amazon — Apple Books, Kobo, B&N, Google Play. Opposite of "KU exclusive".
- Whisper-sync
- Amazon feature pairing ebook and audiobook so the reader can switch seamlessly.
Z
- Zon-tracker
- Generic term for an Amazon BSR / sales tracker (Helium10, Bookreport, our Sales Tracker, etc.).