HN does not use the popularity of previous stories from that domain as a weight. It uses the number of votes, adjusted for the amount of time it's been since the link or comment was added. So if a story has 8 votes after 1 minute, it will rank much higher than a story that has 8 votes after 1 day.

details: http://blog.linkibol.com/2010/05/07/how-to-build-a-popularit...