Ebooks haven't exactly set the publishing world on its ear. Calling ebook sales "disappointing" is an understatement. For years, ebook proponents touted percentage increases in ebook sales (after all, going from $10,000 to $20,000 is a 100% increase), extrapolating those increases to sales levels of "billions and billions" by the turn of the century, if not sooner.

Early projections had print books becoming obsolescent by 2001, or losing half their market to ebooks by then. By 2000, pundits disclaimed any notion that print books would really go away, but ebooks were still a sure thing. In 2001, Accenture projected 28 million dedicated ebook readers in the U.S. by 2005 and $2.3 billion in 2005 text sales for those devices. Forrester projected a more modest $251 million in ebook sales for dedicated readers in 2005 (plus $423 million in ebook sales for other devices)—and another $3.23 billion in digital textbook sales. RCA, making ebook appliances at the time, dismissed Forrester's projections as "ridiculously low."

So what happened? If you believe the International Digital Publishing Forum, 2005 worldwide ebook sales were up 23% from 2004—to just under $12 million, considerably less than Forrester's or Accenture's projections. By comparison, the total U.S. book publishing market was between $25.1 and $31.6 billion—up more than a billion from the previous year. Worldwide ebook sales represent about 1% of the increase in U.S. book sales—but less than one-twentieth of one percent of total U.S. book sales. In other words, ebook sales might just amount to a rounding error in overall book sales.

I see seven reasons ebooks are doing so badly: First and foremost, for most readers and most books, ebooks are a solution in search of a problem. Print books work. Most readers see no need to replace print books. That's why I believe ebooks won't be more than 25% of the market in my lifetime. But why can't they even reach 1%?

The old problem of ergonomics still applies. Despite advances in displays and the current promise of e-ink/epaper, most people still find paper books easier to read. That should be the easiest problem to solve, but the solution keeps slipping away.

Digital rights management causes compatibility problems that sharply limit ebook potential. You should be able to buy an etext that will yield a satisfactory "book experience" on your dedicated reader, tablet computer, PDA, notebook, or even (shudder) cell phone. You should be able to start a book at home on your tablet and finish reading it on your PDA. Right now, DRM usually prevents that.

DRM also exacerbates the fourth problem—pricing—by making an ebook less valuable than a paper book, even though it probably won't cost any less. When you finish reading a paper book, you can give it to a friend or sell it to a used bookstore; neither is possible with most ebooks.

The other three reasons could be opportunities. Improvement in these areas could help make ebooks a healthy business, possibly a multibillion dollar one. First, ebooks need to aim at niches instead of the moon. Tailor ebooks for areas where they work better than paper books. The biggest niche is textbooks, if other problems were solved. It's happening already to some extent with reference works, except that they're becoming databases rather than ebooks. Forget replacing mass-market paperbacks; ebook vendors should look to replace bulky, overpriced, hard-to-update, print books.

Second, ebooks should do things print books can't do. Not dreams of "books talking to books" on some grandiose scale, but forms of interactivity and extended resources that serve specific needs. That also happens in small areas (e.g., some medical works); it's not clear that there are huge areas where this matters. One sizable area, books with such a small potential market that mainline publishers won't touch them, is no longer on the table: print-on-demand can make anybody a publisher of "real books" with little investment or risk, which is one reason there are now more than 50,000 small book publishers in the U.S.

Finally, one you don't see mentioned very often: Ebooks are for book readers, not for vidiots and gamers. If someone's not interested in reading a book-length text, putting that long text on an electronic device won't make it more palatable.

Will ebooks displace most print book sales? Probably not. Can ebooks become a big enough market to care about? Certainly—but not with the way things are going. Even as an ebook skeptic, I hope that changes.