With the exception of job ads it's algorithmic. Stories are ranked by points (from people voting by clicking the up arrow) divided by some non-linear function o

With the exception of job ads it's algorithmic. Stories are ranked by points (from people voting by clicking the up arrow) divided by some non-linear function of time. If a story gets any votes within the first few minutes, that's usually enough to put it somewhere on the front page. Your link only got a couple of votes, so as time progressed it dropped in position fairly quickly until it was gone. Compare your story (10 points) to the current front page (248 points for the #1 link).