Amazon and social software
Josh has an excellent post reviewing Amazon's investments in social software. (Thanks also to Brian for all the analysis). I agree they're good, and we've taken a number of clues from them including a hard-core focus on purpose-driven social software design. And clearly they're a reasonable general model, but I wouldn't take it much beyond that.
Amazon's social solutions are designed to help people sift through countless purchasable goods, and few of us have that problem. Some of the techniques they employ can be re-purposed to solve other problems, recommendations fall into this category, and that's fine as far as it goes. We're clearly into it. But the point is, don't just copy Amazon -- design your social systems for your users. For example, to what extent is "connection", or one-way, two-way, 1:many communication important, and in what fidelity. Ask yourself what goals your users have and what key activities will they pursue. In social systems like those we build for Microsoft, affiliations are key -- think MVP program. And there are lots of other examples -- access to the best information flows also comes to mind, as does reducing customer and Microsoft pain associated with support.
Also, Amazon's social solutions consist almost entirely of no-tie associations. That may be fine for them -- though I suspect they'd prefer it otherwise. (In fairness, some of the benefits of weak-tie associations are had in the form of the "other people bought this" feature.)
Finally, for many of us engaged full time in social software design, we assume our systems will form a daily experience, ideally many times daily, for most of our users. Personally, I check in with my professional social network many times a week -- I may skip days, but I'm more often in the many times a day camp. It's my morning paper, my during lunch reading material, and sometimes my bedtime reading. That's the way it is for most successful social solutions: WOW, Second Life, Myspace, del.icio.us, Facebook, or by far (IMHO) the most useful social network -- the one in your RSS reader.
Now I'm a real fan of Amazon, but if I'm there more than a few times a week it's a lot. I don't have any research one way or another, so I don't know if that's a lot or a little. My quick check (asked the folks in the adjoining offices) suggests my number of visits is on the high end. And the vast majority of my trips ignore the social features they have to offer because my social network sources the books that interest me. I visit Amazon after the fact and typically only to purchase.
So Amazon would get my vote for social software for the online low margin breadth retail marketplace. If you're interested in books, my vote for best social solution on the net is http://librarything.com. Be warned though, it's all about books. If they'd integrate their tagging solution with their forums, they'd be even better. BTW, I've heard Amazon has about five percent of the tags that Librarything boasts -- these guys know how to make tagging work. Hint: they know it ain't about the tags...