It may not feature young wizards or teen bloodsuckers, but Dan Brown's The Lost Symbol is still drawing cheers from the book industry. 

The latest entry from The Da Vinci Code's author hit stores yesterday, and it's already the top draw at Amazon.com (NASDAQ:AMZN) and the online storefronts of Barnes & Noble (NYSE:BKS) and Borders Group (NYSE:BGP).

I don't get it, though. Who's buying this book at bn.com or borders.com? They both sell the hardcover version for $17.97, a seemingly thick 40% slice off the list price. Amazon, on the other hand, is selling copies for just $16.17 apiece. Barnes & Noble shoppers can nab Amazon's price, but only if they pay $25 a year to be part of the chain's membership program.

I understand the flexibility to charge more at the physical storefronts. If you're at a Barnes & Noble or Borders superstore, you expect to pay more for instant gratification and the actual distance between real-world alternatives.

But cyberspace, where every competitor is a click away, is a different story. Naturally, the bookstore chains have a quandary. If their online discounts are too steep -- the only way that they will ever compete against Amazon.com -- they risk making shoppers at their  bricks-and-mortar stores feel cheated. Then again, this can't-win scenario also explains why Amazon can't lose.

It also doesn't hurt that Amazon's Kindle is making dead-tree books a thing of the past. Since yesterday, Amazon's top-selling item has actually been the Kindle version of The Lost Symbol.

This doesn't necessarily mean that Amazon will move more $9.99 digital copies than $16.17 hardcover versions. Amazon's bestseller list is updated hourly, and hardcover preorders have been selling briskly for months. Kindle owners can preorder books, but why would they? There's never any question whether a Kindle file will be available in Amazon's inventory, and digital deliveries are completed within a minute.

Digital delivery is inevitable. Beyond Amazon, Sony (NYSE:SNE) is a spirited competitor in this market, with Apple (NASDAQ:AAPL) and Google (NASDAQ:GOOG) taking baby steps in e-books' direction as well.

How profitable can the market be? Will publishers be able to make more at lower price points, given the inherent cost savings of digital delivery over physical printing, shipping, and swallowing down of returns? That's a thrilling page-turner that even Brown can't decipher.