What I love most about blogs is that at the end of the day, whether or not I decide to add one to my feedreader is solely a function of the writing. It's the purest form of meritocracy.
Take Violent Acres, for example. Her most recent post happened to hit the Digg front page (which is how I found the blog), and I decided to add her feed. As I did, I noticed that about 400 other Bloglines readers were already subscribers (a decent size). What I also noticed was that it didn't really matter to me whether she had 0 readers or 50,000--all that had crossed my mind was, "I really like her voice and her writing. I'm going to subscribe."
Obviously, it helps to hit Digg's front page. But attention is fleeting. All it does is open the door. It's your writing that gets people to walk through, instead of whistling past.