People resist change. It's only natural. So when POD books entered the market, some immediately began to question their quality and their durability. Why change to new-fangled things when offset has served the world so well for so long?

Well, here is a reality check. A book product is as good as its manufacturer. American printers are, as a rule, very good manufacturers when it comes to the actual printing. Binders, that's a different story. If a binder uses substandard glue, or processes the production line too fast, problems will show. The most common consumer beef: spines that crack, pages that come falling out.

It happens, and alarmingly it happens more and more. Generally not to POD books, though. When books come apart, it is usually an offset product. Not only that, it is usually a book from a major publishing house, such as Warner, HarperCollins, TOR, Simon&Schuster, Little Brown, St. Martin's, and the blacklist also includes the entire Harry Potter series by Scholastic.

Experts mostly blame the glues. They say too many books seem to be manufactured with cheap adhesives that don't maintain a grip. Sometimes the text block itself comes apart, at other times the text block stays together but does not hold to the spine.

Tellingly, glue manufacturers agree. In the current recession-type era the big publishing houses are cutting costs, and corners. Manufacturers are substituting low-grade glues and inks for the good stuff of years past. And guess what, ink may be the worst evil-doer after all, the very ingredient that digital printing skips. What is called "ink migration" might be the root cause of many of the incidents. Books that contain graphics, for instance, or other illustrations, often use inks that contain solvents. The solvents migrate toward the backbone and eat away the adhesive, especially when the book is stored in a warehouse, and exposed to temperature changes.

That's the fate of offset printed books. They require ink, and they require storage, often for months at a time. POD books have none of those issues. That is why there are so few complaints about them. And when there is a complaint, it is always about the glue, not the printing technique.

Currently, 20 percent of all the titles that are in print are printed the POD way, for a total of 4 million books per year. More than 2,300 publishers are now using this printing technology, including all the major publishing houses. Random House is the biggest producer of POD books.