How Has Your Site Become a Star on Social Bookmarking Sites?

So, you've started a blog. You sign up for social bookmarking sites Digg, StumbleUpon, Delicious, Reddit and maybe even more and start linking your posts to these, commenting on others' posts and adding friends to your networks. But whenever you log in to these sites to see how many "views" you are getting or "Diggs" or whatever, you keep seeing that you have either zero or only one. And when you look at your site's traffic analytics, you see you are getting virtually none from social bookmarking sites. What are you doing wrong?