Could 4 percent of the U.S. population own Kindles in five years? That's what analyst Jim Friedland of Cowen & Co. is saying about Amazon.com's electronic reader.

Given how few Kindles I've seen "in the wild" in Seattle, that projection seems pretty high, though a lot could change by 2014.

Amazon.com doesn't share sales data on its Kindle readers, so analysts have to read the tea leaves. Friedland believes Kindle will become a meaningful part of Amazon's business, with device and content revenue reaching $2.3 billion in five years -- accounting for 10 percent of Amazon's North American sales.

Here's more from his research note, via Barron's:

We expect growth to be driven by: low-cost marketing on the homepages of Amazon's 50-55 million U.S. users; lower prices for ebooks versus traditional books; declining device prices driven by cost efficiencies from higher unit volumes; potential adoption by educational institutions; and we believe it is unlikely that competitors will be able to make a dent in the iTunes/iPod-like position the Kindle is building in the market.

The relatively high price of e-readers does appear to be an obstacle to mass consumer adoption, though that's showing signs of changing. Amazon recently knocked down the price of its Kindle 2 reader to $299, and Sony is launching a new $199 reader, heralding a possible price war. Amazon's new Kindle DX, however, still retails for $489.

Friedland doesn't think Apple's rumored tablet, which some see as a potential threat to Kindle, will have a big impact on Amazon's e-reader business, for a host of reasons:

a tablet is unlikely to use a high-contrast paper-like black & white screen that is tailored for reading and cannot support color or video; Amazon has a time-to-market advantage of two-plus years on the Kindle device and 14-plus years on the online bookstore; Amazon offers rich content in its store, such as user/editorial reviews, that cannot be easily replicated; the Apple Tablet is likely to cost twice the price of the Kindle 2; the tablet will not be able to compete directly with the Kindle unless it has an always-on 3G wireless data connection; and books purchased from the Kindle Store can be viewed on the iPhone/iPod Touch using a free Amazon app, which will likely be compatible with the Apple Tablet.

The Amazon-Apple maneuverings around the e-book market will be key to watch in the months ahead.

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