1. You have few decent comments and a ton of comment spam.
  2. You have people linking to your posts - finally.
  3. When you have consistently increasing traffic/subscribers for the past few months
  4. When you spend a whole day thinking about what to blog about.
  5. You get a call from a headhunter who's looking to hire a Chief Software Architect for a local wireless company and says he got your name from a webblog.

I got that call today, but unfortunately, Microsoft treats me well and I hate to have to change my blog URL again and start all over ;)