This is the response Amazon.com sent to customers who complained about their "pay for referral" policy, which was revealed in a front page story in the New York Times.

 Thank you for writing to Amazon.com with your comments.
 
 Please be assured that our recommendations are not for sale.  We take
 our customers' trust very seriously, and our editors stand behind
 every one of our recommendations.
 
 However, we realize that there has been some confusion over
 Amazon.com's co-op policies.  Here's what we're doing to address those
 concerns:
 
 - By March 1, 1999, our site will list every co-op placement in a way
 that's easy for customers to identify them.
 
 - We've strengthened our returns policy to reflect our confidence in
 the quality of our editorial recommendations.  If you buy a book on our
 say-so, and you're disappointed in it, you can return it, whatever its
 condition.  Even if you thought the book was so bad you ripped the pages
 out, just return the pieces to us for a full refund.
 
 That said, we're proud of our editorial recommendations.  They're
 honest and informed.  Our editorial staff--the largest of any online
 store--combs through thousands of titles each week, looking for the
 best books to feature in our store.  We only feature books we think
 our customers want to know about, and we only endorse books we love.
 As always, customers are free to disagree with us about how good a
 title is, through customer reviews.
 
 We do accept publisher cooperative marketing funds, commonly called
 co-op.  Most book stores do, everyone from cozy neighborhood bookshops
 to giant megastores.  What do publishers buy with co-op funds at
 Amazon.com?  Our promise of when and where we'll feature a particular
 title.  But if a book doesn't meet our standards, we won't feature it
 for any price.  Period.  Our editors regularly reject titles that
 don't make the grade.
 
 Why do we accept these funds in the first place?  Co-op helps us keep
 costs low and our discounts to customers high.  We want to offer you
 the best titles at the best possible prices--and that's what we'll
 continue to do.
 
 Please let us know if you have any further questions or concerns.
 Thanks for writing, and thanks for caring so much about our store.