The Urban Long Tail
An interesting idea: the urban long tail. Steven Johnson suggests that "the long tail premise has a tacit anti-urban bias to it, since it used to require big city scale to find obscure long tail books or albums that are now readily available to anyone with an Internet connection." But he goes on to argue that "some long tail services can’t be Fedexed or downloaded — people, for instance", and describes how you’d have more luck meeting other fans of Scandinavian doo-wap if you’re in Manhattan rather than the middle of nowhere. Elsewhere, he goes on to describe how Dodgeball addresses this urban longtail of people.
I would also suggest that urban environments supply experiential longtail services. Cities can provide direct access to a plethora of niche experiences, buildings, places, views, things – as well as people. I look forward to the day when locative services are capable of mining the richness and diversity embedded within cities, according to the specific needs of the user.