Scoble’s got a lovely post up about digerati, normals, and marketing. It’s worth a complete read, but the summary would be that early adapters are passionate, the American hordes are dull and not passionate (about technology tools, that is), and everyone trying to broaden their installed base would do well to:
a) use Friendfeed
b) load your pages fast
c) be well indexed in Google and have decent SEO
d) know who your audience is and if you want the masses, swing for the fences with some mainsteam marketing tactices, like getting a celeb to use your stuff.
My own thoughts, as someone building an app I hope a wide range of users will use (and as someone who ran a mainstream service for dating)is that Robert’s points are all right on, but the other critical piece is this: build something that people will want to use because it solves a particular problem better than everything else out there, or offers a degree of control and expressiveness the rest of the market doesn’t, or can’t Then take every bit of Robert’s advice..