The company that drives online replications of many leading magazines has extended its service model to books. With Harvard Common Press as its first client/partner, Zinio has added a digital cookbooks section to its web site. Featuring about 90 titles, the site sells them at a 20 percent discount to retail price. As with magazines, the pop-up Zinio reader flips pages with a click, and renders full-color replications of each book page in two-page spreads.AnnouncementZinio site