Shiri Lev-Ari at Haaretz.com investigates what has happened to all the old books:
In a very competitive culture that emphasizes newness and fashion, and promotes the reading of a current blockbuster which is forgotten in a moment’s time, the backlist is a vanishing phenomenon. The volume of sales of one-year-old or older books is shrinking, while newer books capture an increasing share of the market. Most major publishers realize that this ratio has changed. The scope of the decrease is estimated to be 20 percent: the backlist which once accounted for 60 percent to 70 percent of the sales volume now represents 40 percent to 50 percent, depending on the size and age of the publisher.