Amazon’s recent acquisition of ABEbooks has by extension given it a 50% stake in Library Thing which is a little awkward as Amazon was an early investor in competitor Shelfari. Perhaps we can expect both services to be integrated at some point. I use and like both. Library Thing launched first and has the bigger community but Shelfari’s user-base is coming along, no doubt helped by their early controversial spamming and astroturfing tactics (which is incidentally how I came across the site, unethical maybe, effective definitely).

Shelfari seems to be going after the less technically-minded users, focusing on ease of use and cute widgets. Library Thing offers more functionality and is generally a little geekier but deeper. The biggest difference is that Library Thing charges users to catalog more than 200 books whereas Shelfari’s business model depends on taking cuts of book purchases made via the site.

It will be interesting to see what the effect of Friend Connect and Facebook’s development and feature-creep will be on the myriad social-network sites built around different topics and interests. Friend Feed has been an excellent precursor to a web where our social networks are aggregated. Ultimately all of these various networks (flickr, delicious, shelfari etc) may be usurped by or almost totally dependent on a more openly-connected and feature-rich Facebook. FB is increasingly becoming my central non-professional communications platform. Being able to carve out different layers of sub-groups within your Facebook friends would be a useful step in that direction, so I can for instance add my ‘reading’ friends to a subgroup which is alerted everytime I buy or review a book etc. At which point, both Shelfari and LibraryThing could become superfluous.