Why Facebook Works for All, Twitter for Some

I read once that the surest way to identify an engineer driven company was to look for user elements that work like data structures. Between the @'s, the #'s, and the other various syntactical quirks, Twitter sure seems to fit that description well.

On the other hand, however, I'm not sure that's only a bad thing. The barrier to entry is present but not insurmountable, and it gives the "Twitterati" a clubby sort of feel. Everyone wants to feel special - back when Facebook was invite only, people would claw and clamor for invites. There's a balance in there, and it seems like Twitter's gotten close. Not perfect, but close.

The biggest single mistake of most software designers is to underestimate the importance of usability. If there is any significant usability difference between two products, consumer selection will favor the more usable product.