Would you buy a book that had ads in it? What if you had a choice, the same book with ads or without ads? And what if the book with ads cost less, say $12 instead of $28? And what if you could get a bigger discount with even more ads? And if you could even pick the type of ads? These are all options being considered by publishers. Print-on-demand technology will make it possible to give you the choice.

Advertisements inside of books is nothing new. According to Paul Collins in a New York Times article, an 1849 edition of David Copperfield contained ads for Freeman's Spermazine Wax Lights (some kind of candle), among other things. The practice died out for a time, then returned. Here's a Penguin paperback from 1944 has an ad for Mars Bars at the back.  

In 1959, the American book publishers started binding ads inside books, mostly paperbacks. They started with ads for Carnation milk and Q-Tips in a Dr. Spock book about child care. Ads became common in science fiction paperbacks as well as Agatha Christie mysteries, the Executioner series, and especially pulp novels. You could also find ads in popular history paperbacks, in a collection of Roald Dahl's short stories for adults, and in Heloise's Kitchen Hints. Literature was not exempt – Toni Morrison's The Bluest Eye and Michael Frayn's Against Entropy contained cigarette ads.

When cigarette ads were banned from TV and radio in 1969, tobacco companies turned to books for ad placements. This continued until 1983 when a survey (and falling tobacco sales) revealed that smokers didn't read much. Although cigarette ads were the most common, you could also find ads for coffee, alcohol, Kotex, dish soap, and cologne in paperbacks.

Although full page ads in books disappeared after 1983, other types of advertising within books continues. In 2001, Fay Weldon wrote The Bulgari Connection. For mentioning Bulgari at least twelve times in the book, the Bulgari jewelry company paid her £18,000.

In 2006, a young adult book for girls was published, called Cathy's Book: If Found Call (650) 266-8233. It's filled with references to Cover Girl products, in an agreement with Cover Girl's owner, Proctor & Gamble.

These recent innovations in advertising in books haven't really caught on. However, expect to see some attempts at ads in e-books. Print-on-demand is another possible target for advertisers. There are already a few Borders bookstores that have a print-on-demand kiosk in the store. If a customer wants a discounted price, he might agree to accept a book with some advertising in it. It would be very easy to customize a book this way without alienating the people who don't want ads.

Spermazine Wax Lights, anyone?