Used book sales “threaten” the publishing business

Bob Tedeschi writes:

Is Amazon.com becoming the Napster of the book business?
The analogy may not be far off, say some observers of the used-book industry. Publishers, particularly textbook publishers, have long countered used-book sales by churning out new editions every couple of years. But the Web, particularly sites like Amazon and eBay, have given millions of consumers an easy way to find cheap books – often for under $1 – without paying royalty fees to publishers or authors.
Mass-market publishers are not certain the used-book phenomenon is a problem worth addressing, but others in the industry have already made up their minds.