What's the value of the spoken word? $300 million, according to Amazon.com, which just purchased the leading digital audiobook reseller, Audible.com. The amount is a premium of more than 20 percent on yesterday's closing price. The purchase of Audible, which just celebrated its 10th anniversary, shows that Amazon is serious about digital content. Amazon has sold Audible's audio downloads since May 2000, and the purchase is a natural fit as Amazon offers more content via digital delivery. But what does it mean for the consumer?

In addition to selling audiobooks through Amazon, since 2003 Audible has been the sole provider of audiobooks through Apple's iTunes store. Details of Apple and Audible's deal have not been made public, but we doubt that it will be renewed when it expires. For Amazon, this a bit of a broadside against Apple. Amazon launched a DRM-free music store last year and managed to sign up a number of record labels which have thusfar refused to offer DRM-free music on the iTunes store. The music-store arms race shows no signs of cooling down.

But what about the iPod, the natural destination for Audible's audiobooks? The Kindle, Amazon's recently released e-book reader, has a bare-bones MP3 player and could be a possible delivery mechanism for Audible's wares, as it has a wireless Internet connection built in — EVDO, not Wi-Fi, so it works almost anywhere.

Amazon is serious about digital distribution — and has a chance to challenge Apple's dominance in this market like no other digital store has.