The impact of Hacker News on my web site
That graph was taken from GetClicky. It shows the hourly visitors to my web site. The strong line is the day when the article was posted. The other line is from the day before.
That hump represents about 2000 visitors who came mostly from Hacker News while the entry got about 40 points on HN.
This article was posted as well, to see the effect of a recursion.