The Internet and word-of-mouth helped get Eric Volz released from a Nicaraguan prison. So it makes sense that he’s now using those channels to help market his book about the experience.

An American who moved to Nicaragua in 2005, Volz was convicted in February 2007 of murdering a former girlfriend in a trial that summarily dismissed virtually all the evidence proving he was nowhere near the crime scene at the time of the murder. In December 2007, an appeals court overturned his conviction and released him from prison.

Now Volz has written a book, Gringo Nightmare, and created a complementary Website. Each copy of the book includes an access code that the reader enters onto the site to gain access to videos, audio, photos, and documents that correspond to notes in the book. These multimedia “exhibits” support the facts of the case and provide additional color. The site also allows visitors to comment on the exhibits.

Posting the corroborating legal documents online allowed Volz to keep the narrative of the book flowing without “marginalizing the legal validity of the case,” he explains. What’s more, “there was so much in the story you have to experience” that the printed page doesn’t accommodate—something that every direct marketer who started out in print before expanding online can certainly understand.

Indeed, comments on the site attest to the power of enhancing print with online media, in the same way that e-commerce sites with rich media applications can enhance shopping by catalog. As one visitor wrote, “The audio, pics, and vid add such a strong element to the personal experience while reading the book!”

Gated online content, which is what these exhibits are, has been getting a lot of attention lately, as more newspapers are putting content behind paywalls. As far as I can tell, though, Gringo Nightmare is the first book to provide ancillary gated content. I expect more to follow suit, especially as e-readers and tablets gain more traction. But access codes to restricted content can work for marketers too, perhaps as part of a loyalty program or to encourage e-mail sign-ups: “Subscribe to our e-newsletter and gain access to member-only promotions and product previews,” for instance.

That’s not the only marketing-related slant to Volz’s story. GringoNightmare.com links to another Website, FriendsofEricVolz.com, that Volz’s parents had set up shortly after his arrest. Their purpose was simply to keep friends and acquaintances up to date on the case. But then some of those contacts suggested using the site, and the Internet, to raise funds for his legal costs, conduct letter-writing campaigns, and raise broader awareness of the case. Supporters subsequently created a “Free Eric Volz” page on MySpace (don’t forget, this was way back in 2007, when MySpace was still more popular than Facebook in the States) and a seven-minute video they posted on YouTube. The video, says Volz, was the first time YouTube was used effectively to promote a social cause. It soon received more than 100,000 hits (today it has more than 200,000), and YouTube even placed it on its home page as a sponsored video, which further helped to spread the word.

The Internet was, Volz says, “very important in getting the media’s attention.” This attention, from media in North and South America, highlighting the corruption of the Nicaraguan court system, contributed to the appeals court’s decision to release Volz.

That Volz “already had a very engaged group of supporters,” as he says, courtesy of the Web, also no doubt played into St. Martin’s Press’s decision to acquire Gringo Nightmare. Those supporters, and Volz himself, are now using YouTube, Facebook, Twitter, and the like to promote the book, which like the overwhelming majority of books published today, has virtually no marketing budget .

Accompanying the overwhelming growth of social media has been a backlash against it. Some traditional marketers still insist that social networks are a waste of time in that they deliver little in the way of measurable revenue. Perhaps, but consider this: While social media helped raise grassroots support for Volz, arguably their greatest feat was attracting the attention of the mainstream print and TV media, which in turn attracted the attention of higher-ups here and abroad.

Those who pit one medium against another are missing the point. While your marketing story should be able to stand alone in the medium of your choosing, if you can use multiple channels to amplify the message, you should.