[Zak]

Recommendation engines aren't all bad. I think one of the keys to making it good for users is to derive recommendations from stated preferences rather than supposed revealed preferences.

That is to say a good recommendation engine would not use viewing, replying to, or otherwise interacting with content other than using a button that says "show me more like this" as an indication the person wants to see more like that. This is, of course not compatible with short-term profits for a site that monetizes time-on-site, but could work with such a profit model over the long term.