Behind Amazon.com’s purchase of new Hewlett-Packard presses and its plans for print-on-demand.

Amazon bolstered its print-on-demand (POD) book division and consequently put the rest of the industry on notice that retail distribution is continuing to change, after it made a significant push to add new digital color presses to its operations.

The leading online retailer would not publicly disclose the number of Hewlett-Packard (HP) presses that it purchased or the price paid, but said several HP Indigo presses and production manager controllers were installed and put into operation in a number of the company’s fulfillment centers, when the announcement was officially made in December 2006.