QUESTION: I've got a bunch of books that are practically worthless on Amazon Marketplace. Should I give them away? Why do sellers even bother listing things worth less than $1? What am I missing?

ANSWER: You're right, it's not worth listing a book for sale unless you can reasonably expect to make a few dollars' profit.

It used to be possible to squeeze about 50 cents of profit from selling "penny books" on Amazon -- assuming the seller got the book free, it weighed less than a pound, and could be mailed in a cheap bubble envelope. Several Marketplace penny sellers with access to cheap paperbacks built businesses around 1-cent books.

But since the Postal Service raised rates (and Amazon didn't raise shipping credits for sellers) the days of squeezing profits from shipping fees are over.

Yet some sellers still offer two rationales for selling cheap books:

1. Building your feedback score.

Sure, it would be great to build a track record as a seller without spending much on stock, but it doesn't work very well. Customers who buy cheap books are notoriously hard to please. You'd think someone buying a book for a penny wouldn't have much to complain about -- but believe me, they find a way. These are the folks who will e-mail you daily when their book doesn't arrive after four days. These are the folks who complain that shipping cost $3.49 but you only spent $2 on postage. And so on. Not all penny-book buyers are a pain, but an unusually large percentage of them are. On the other hand, the folks who pay $75 and up for a book are usually the ones who have nothing but good things to say -- if you hear from them at all.

2. Retaining e-mail addresses.

Selling books only to mine Amazon e-mail addresses is not a great idea either. Amazon's participation agreement prohibits sellers from contacting buyers except to fulfill orders. In other words, Amazon can (and does) boot sellers from their site for unauthorized contact with buyers or disclosure of customer information.

And with all the recent trouble over e-mail viruses and phishing scams, it's only a matter of time before Amazon eliminates direct e-mail contact between buyers and sellers anyway. They've already rolled out a Web-based contact form for buyers' questions.

The bottom line is, if you have some cheap books on hand, save yourself some headaches and donate them to your local library or charity.