Glossary
ASIN
Also called Amazon Standard Identification Number
An ASIN is Amazon's own product number, which it gives every item in its catalog, including each Kindle ebook.
What it means
ASIN stands for Amazon Standard Identification Number. Amazon gives one to every product it lists, from phone cases to paperbacks. You can see it on a book’s Amazon page under “Product details”, and in the page’s web address.
When you publish a Kindle ebook through KDP, Amazon gives it an ASIN. You do not need an ISBN for that ebook. A thriller published only on Kindle may have an ASIN and no ISBN at all. A memoir with a paperback and an ebook will have an ISBN for the paperback and a separate ASIN for the Kindle edition.
The ASIN only means something on Amazon. Other stores, libraries and distributors do not use it.
Why it matters when you sell direct
Your own store does not need an ASIN. Readers buy from you by title and format, and your ebook file is the same EPUB whether or not Amazon has a number for it.
Authors sometimes worry that selling direct conflicts with their Amazon listing. It does not, unless the ebook is in KDP Select, which asks for the digital edition to be exclusive to Amazon. Your ASIN stays the same either way.
How Lanternbee handles it
Lanternbee does not use ASINs. Each edition can carry an ISBN if you have one, and readers can send ebooks they buy from you to their Kindle without any Amazon listing at all.