-Not Related to Cars-
Digg promotes content to the top page where news stories are more likely to be read. Stories make it to the top when other Digg users vote on the stories, pushing them forward.
Anecdotally established users have a greater probability of having their stories make the front page compared to other, new users. Digg’s community has reweighted the social inputs for these people. Digg also works in the opposite direction; people that try to spam digg can have their accounts banned.
Lesson here: if you want to use digg to promote your article on how to buy a used car, make sure to interact with the digg community first and build trust.