Booklovers have another reason to warm up to (NASDAQ:AMZN). The world's leading online retailer is buying Shelfari, a social network for reading fans, for undisclosed terms.

Shelfari members create virtual bookshelves, stocked with the book covers of their favorite reads and the books they are currently reading. They share critiques, see what their friends are reading, and can discover new books by seeing the most popular reads in different genres.

This isn't the first time that Amazon has gotten bit by the Web 2.0 bug. It acquired film buff hotbed years ago. When it acquired AbeBooks earlier this summer, it also came with a minority stake in Shelfari rival LibraryThing.

The obvious integration is to have Shelfari entries link to Amazon books. It can even offer members a financial incentive by cutting them in on any resulting commissions as it does with its Amazon Associates program. Milking that viral moneymaking cow while retaining the integrity of bookworms is the key to masterful juggling.

The bigger opportunity, of course, rests in bringing the graphically stimulating and chatty Shelfari interface to Amazon's own bookstore. The Seattle-based retailer has never been under pressure to make shopping social or even fun, but now that eBay (NASDAQ:EBAY) is going after more conventional retailers like Amazon and Overstock (NASDAQ:OSTK) by lowering fixed-price listing fees, making Amazon fun for those who need a little more interactivity than the checkout process is important.

Yes, sites like Amazon and Netflix (NASDAQ:NFLX) are Web 2.0 in theory. They encourage buyers to leave product reviews, and use that data to make custom-tailored recommendations. Amazon also offers discussion boards based on its wares and encourages active shoppers to put out themed lists for others to read.

However, if online shopping is going to truly replace the mall scene, it's going to have to step up the social aspects of the shopping experience. This is an intriguing step in that direction, but we still can't read too much into it. Amazon has had IMDB for several years and the actual integration with Amazon has been minor.

So Amazon shareholders can welcome Shelfari members with open arms, but they better know that there are a lot more chapters left before they live happily ever after.

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