Understanding Book Returns
Book publishing is a returns-based business, which means authors who want to compete with other authors—whether they are large or small—need to accept this reality. If you’re an independent author and you want your book to be available to bookstores, libraries, wholesale markets, and beyond, your book must be returnable and set to standard discounts.
According to industry reports, your publisher, by default, is adhering to industry expectations when it comes to discounts and returns. Your book will be selling your book to accounts between 40% - 65% off the list price and will be allowing for your inventory to be returned to its warehouse (for a full refund, plus return fees) if it doesn’t sell. 
Understanding book returns require three basic concepts in retail packaged goods sales:
1. Sell-in: how many units the retailers order to put on shelves.
2. Sell-through: how many units the retailers sell to end users. Sell-through is the top benchmark of book selling.
3. Returns: excess inventory that retailers ship back to the wholesaler. One of the basic concepts of book sales to understand is “book returns.”
Authors who have written and sold books understand that a “sell-through” means how many units of the book that retailers sell to end users and is the top indicator of a book’s success. When you see your sales reports, it is important to realize that book returns are a normal part of book selling and should not be alarming. Any inventory that is unsold is returned and according to industry reports many distributors expect a 25% return rate on each new book. 
If you’re fairly new to the book publishing world, returns may be a bit of a mysterious concept. Even though print on demand services and digital advances have helped the book business better predict book demand, returns are still an inevitable part of the bookselling process if you’ve chosen to make your book returnable. It’s important for you to understand why book returns occur, and to prepare to help with handling book returns.
Returns are a normal part of selling books. Retailers and distributors have computer systems which estimate demand levels, so they have enough inventory to satisfy orders from marketing efforts. Any inventory that is unsold is usually returned.
Something to consider: In many cases, brick and mortar stores such as Barnes and Noble and others will not order a book unless it is returnable. Although there is no guarantee that booksellers will carry your title if you make it returnable, it increases the likelihood that your book will be considered by booksellers if it has a returnable status. Many booksellers pass over titles that are nonreturnable as a rule. Selling books is their business; when they take a chance on a new author, it’s easier for them to justify the purchase to themselves when the risk is eased by a returnable status.
When your title zooms off the shelves, the returnable status becomes irrelevant because there is no book to return. They may even order more if your title performs well for them! What is positive: the fact that your book is returnable helps encourage booksellers to give it a chance in the first place.
Good luck, and I hope your book is one of the lucky ones to gain massive exposure in bookstores!