Social bookmarking and networking sites have a lot in common with celebrities: They gain a fan club or following. Their reputation can be made or broken as a result of media publicity. And they must stay hot and interesting in order to stay on the lips of the people who talk about the industry. And just like with Hollywood’s stars, today’s favorites can be tomorrow’s has-beens as new players come in to the game.

In the world of social bookmarking, the paparazzi are currently all over Mixx. The site popped up on the scene like a supporting actress who steals the show. If that’s the plot of the movie, the starring role went to Digg. And if that’s the plot of this movie, it seems that Digg is going to need to move on to other roles if it wants to stay on the screen. Otherwise it runs the risk of being just a tired old celebrity trying too hard to stay young.

Digg has long been the star of the social bookmarking scene. Even if you don’t do bookmarking yourself, you’ve probably seen the “digg this” button on many of the blogs you read. Essentially, it’s a voting system that allows you to submit articles that you like in order to get others to read them. It’s a method of promoting your own writing and the writing of others. And it can also be used to find interesting information that you might not have otherwise come across.

But lately, Digg has been getting some negative media attention. A star can only stay unsullied for so long. Digg has a number of practices that were starting to annoy its users. For example, good stories were getting “buried” (or bumped out of sight) by people who like to “vote down” the submissions of others on the site. Additionally, Digg has a habit of kicking off users for inappropriate submissions, and it often does this poorly so that good users are sent away. For a long time, users continued to visit the site because Digg was still the leader in social bookmarking.

But then Mixx came into the picture. With the help of news articles and press attention, Mixx began to steal the spotlight from Digg. It took the best qualities of the site and used them to create a new social bookmarking platform that didn’t seem to have any of the problems that Digg users were reporting.