We've always thought that authenticity was a key attribute of a successful web service. We define authenticity as that intangible feeling you get when you come across a service that does exactly what it is supposed to do, is novel, true to itself, etc. Digg, Delicious, Flickr, and Craigslist are all authentic services and have remained so.
Last night I wondered whether you can fake authenticity. I think not, but certainly many have tried. What do you think?