Enter Amazon Trade-In

Selling books on Amazon, title by title, is nothing new.  By quickly entering the title, a book deacquisitioner (another name for someone cleaning out their library) can see if it's worth selling a book.  Amazon has added a per book fee, plus their percentage, so it is no longer sensible to sell a book unless it's going for $5 or more, and then mostly just to get rid of the book.
A new program called Amazon Trade-In is available for books with decent resale value.  If the book entered has a "Trade-In" button next to it, Amazon shows the standard trade-in value.  It's much less than the online used prices, since the reseller is a 3rd party who needs to include a profit, but it's a quick way to pass along a lot of books at once.  I am sending off 6 hardcovers, shipping is on them, and I will receive a $12 Amazon credit to my account.  It is a sensible, quick way to move books along.  Not a big money maker, but a good problem solver, and recirculates the books.
Their online forum suggests it is not working perfectly.  Let's see what happens.
Update:
I just received online notification of my credits from shipping 7 books at their expense.  One book was rejected, but according to my directions, they don't ship it back.  While I don't know what they do with books that are not resalable, but at least this one is not sitting in my house.  The books are worth very little, but it's great to send 6 books off for not a lot of work.  I am pasting the list, not to encourage you to buy them, but as a demo.

Selected Return Option: Do not return the item. If the item is considered to be in a lower condition, you will receive an Amazon.com Gift Card for a lower amount.

Item	Quantity	Condition	Value	Status
Seeing Like a State: How Certain Schemes to Improve the Huma... ISBN-13: 9780300078152, ISBN-10: 0300078153	1	Good	$6.10	Gift Card Deposited
Thinking in Time: The Uses of History for Decision-Makers ISBN-13: 9780029227916, ISBN-10: 0029227917	1	Good	$2.58	Gift Card Deposited
Why Government Succeeds and Why It Fails ISBN-13: 9780674015890, ISBN-10: 0674015894	1	Good	$1.29	Gift Card Deposited
The Talking Book: African Americans and the Bible ISBN-13: 9780300109368, ISBN-10: 0300109369	1	Good	$0.05	Gift Card Deposited
The Economics of Happiness: Building Genuine Wealth ISBN-13: 9780865715967, ISBN-10: 0865715963	1	Good	$2.67	Gift Card Deposited
The Overloaded Liberal: Shopping, Investing, Parenting, and ... ISBN-13: 9780807001295, ISBN-10: 0807001295	1	Good	$0.74	Gift Card Deposited
Total	6		$13.43

An Amazon.com Gift Card* worth $13.43 has been applied to your account