I say that as someone who regularly works on a fairly large and unwieldy site, where user knowledge of internal terminology is a fairly tenuous thing…..

There are exceptions, of course, and they mostly fall under the guise of “personalization”. I would call Amazon “user-driven”, or at least partially user driven. Many of their recommendations come from the behavior of others on the site, and from my experience their recommendations are very good.

I don’t have an answer of how to do it on most sites, but here’s an example of how Google could make their site more user driven: take the top 10 topics that I search for, and create a personalized news feed or page out of current related items. Google has known for years what I’m interested in, but they don’t seem to take advantage of it. They know I like Apple Computer, for instance. Why don’t they show me the best deals for one?

On the other hand, any site that uses categorization and classification schemes now– particularly homegrown ones– could benefit from at least thinking about how tags might change both production and use. If nothing else it makes one think harder about just how categories and classifications are being made and used.