There are a growing number of sites where a "community" of people are sharing links among each other to useful resources and articles. For your site to become seen in one of those sites can help build popularity of your site. For example being listed on the front page of Digg or Slashdot can draw a crushing amount of traffic to your site, and assuming all that traffic can get to you then it gives you a huge amount of visibility. And if you've done a good job writing a memorable article, that traffic might just return to your site later.
But there's a truism that getting slashdotted or diggdotted is a flash in the pan. That traffic spike just disappears never to be seen again.
In How to Build a ‘Digg Culture’ on your Blog the claim is made that if you can be digg'd repeatedly, that the traffic does build on itself. The author has apparently been repeatedly dugg and has experience with how to ride the wave. He has some good insights and recommendations on the way to be listed regularly in digg, and how to make the best use of the exposure.15 Powerful Ways to Differentiate Your Blog from the Crowd is an article by the author of zenhabits.com giving some advice he learned through building the popularity of his site. He says the site started in Jan 2007 and within one year became a top 100 blog with oodles of traffic. The suggestions are very sound and useful.