's (Nasdaq: AMZN) Kindle Fire was one of the hottest gifts this past holiday season, but its growing popularity has brought more opportunistic privateers to the digital seas. E-book piracy, hardly a new subject, seems to have kicked into high gear -- London's Daily Mail reports that up to 20% of all e-books may be pirated.

That points to rougher sailing ahead for Amazon, which is counting on content sales to recoup the losses it takes selling the tablet. It's likely to be worse for major publishers, unless the industry collectively wakes up to new digital realities.

An old industry in peril
Publishing and the music industry have obvious parallels but critical differences. The music industry has seen its record sales -- including all digital formats -- fall by more than $1 billion since 2006. Publishing, on the other hand, is still reaping rewards from the e-book explosion. E-book revenues grew 1,200% from 2008 to 2010.

Pearson (NYSE: PSO) saw revenues at its Penguin imprints grow by 17% during that e-book boom, though youth-focused Scholastic (Nasdaq: SCHL) lost revenue in its non-educational publishing division during the same period. As with the music industry, content matters -- Pearson has a number of marquee writers on its roster, whereas Scholastic's only notable in-house best-seller (it also distributes other publishers' titles) is Suzanne Collins' Hunger Games.

Biting the hand that feeds
E-book sales almost certainly took off last year, largely thanks to broader adoption of the Kindle, but also with an assist from Apple's (Nasdaq: AAPL) increasingly ubiquitous iPad. Here, again, the music industry's example works well: Apple's iTunes reached its billionth download about three years after the service went live, but it sold 9 billion more songs in the following four years. The first-generation Kindle went on sale at the end of 2007. Four years later, the Kindle Fire is in the hands of millions. The e-book explosion is either here or is about to crash ashore.

In the e-book case, however, Apple's insistence on high margins may undermine faster adoption, as the Fool's Evan Niu reports. Rather than pushing for low prices, as it did with iTunes, Apple encouraged publishers to set their own rates, undercutting Amazon's effort to keep big titles priced below $10. That's led to antitrust investigations that threaten to undermine Barnes & Noble (NYSE: BKS), which uses a similar e-book pricing model as Apple -- but more broadly, unnecessarily high prices only encourage piracy.

Same as the old boss
The Publishers Association, a printed-page analogue of the RIAA, hasn't helped its cause, either. The organization issued more than double the cease-and-desists for piracy in 2011 as it did a year prior. It seems like publishing's completely failed to grasp the iTunes lesson: Consumers are plenty willing to pay for content they want, but they want a fair price.

Amazon's positioning itself well in this battle, having founded several publishing imprints of its own. The company also makes it relatively easy for unheralded authors to get their writing into digital format, cutting out the middleman entirely. Music publishers aren't dead yet, but they're hardly thriving. Book publishers need to learn from the past before they repeat it.

The secret's already out that companies like Amazon and Apple stand to benefit hugely from the mobile revolution. What many investors don't realize is that many more companies are also ready to reward their shareholders equally. Thankfully, The Motley Fool recently released a report detailing 3 Hidden Winners of the Mobile Revolution. Better yet, we made it completely free for our readers. Sometimes the best investments come from lesser-known companies. To find out which companies are poised to thrive in the years to come, access your free copy today.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.