Concerned about what it perceives as Amazon.com's increasingly aggressive steps to promote used book sales, the Authors Guild sent an e-mail to its members last week urging them to de-link their sites from the giant e-retailer. The guild is particularly upset about an Amazon link that tells its repeat customers how much money they can make by selling used items (not just books) through its site.

A growing number of authors have Web sites that promote their own titles and often offer links to Amazon or other Internet bookstores so that online orders—of new books—can be processed. The guild contends that by linking to Amazon, authors are undermining their own new book sales by inadvertently promoting the sale of a used book for which they receive no royalties.

"This is all about the economics of book publishing and how Amazon's practices are affecting it now and how they may affect it in the future," said Authors Guild executive director Paul Aiken. Amazon acknowledges that about 15% of its unit sales in the fourth quarter came from used items, but contends that the lower used book prices introduce customers to authors whose books they have never read. Aiken argues that, while that may be true in some cases, the policy "is definitely siphoning off new sales. If it's at 15% now, where will it be a year from now?" Aiken warned that the trade book business cannot afford to become like the college textbook business, where used books are estimated to account for one-third of all sales.

The way Amazon's used program works, not only are authors and publishers losing sales, but affiliates that refer customers to the site do not receive any money. According to Daniel Gray, author of The Complete Guide to Associate and Affiliate Programs for the Net, "Amazon is selling used books where the referring associate Web sites are not paid a single penny for the referral. Amazon profits from the traffic and the associate gets nothing in return."

The Authors Guild recommends that its members link to Booksense.com or BarnesandNoble.com.