It definitely makes tags more ephemeral, more dynamic and more fluid. That's a good thing. The problem is that in hubski, you have built a social network based on friendship and affinity without recognizing that "common interests" are one of the fundamental basics of friendship. People meet their friends through church, through hobbies, through shared addiction, through all sorts of commonality. If I were to meet Gary Cobain on the street I'd probably want to hit him. But since I'm a big, big fan of the Future Sound of London, I'm likely to extend him a lot of rope as far as his opinions and viewpoints. Likewise, I really like hearing what David Bowie has to say about stuff, which makes me more interested in his music - I stopped listening to Laibach and Echo and the Bunnymen cold having mixed them and interacted with them in person. They're assholes, but you wouldn't know that from listening to their music. (well, Laibach maybe) You see "tag" and think "subject" or "category." I see "tag" and I think "interest." Do you really think members of a model railroad club would hang out together if they didn't have the HO vs N rivalry to tie them together? This expectation isn't related to "tags" it's related to human nature. Both eHarmony and Match.com use the Meyers-Briggs personality test to get their matches. Here's the interesting part: eHarmony matches people with similar profiles. Match.com matches people with opposing profiles. They both seem to work. Personality only takes you so far, though. What do you have in common? This stuff matters. Hate the word "tag" all you like but recognize that you didn't include it out of obligation, but out of societal necessity.