When one of my articles made it to the #2 spot on Hacker News, I was watching my Google Analytics Real-Time stats pretty closely. It got as high as ~700 people on at one point.
(Here's the submission: https://news.ycombinator.com/item?id=5062761)
700 people on the site at one time? Or 700 for the day? 700 at the same time is incredible (to me)! You must have been nervous about your server. When we hit 250 we panicked we would go down!
Sat at a pretty constant 250 online visitors for hours. Pretty sure the brief peak must have been close to 700 as well.
Fortunately Webpop is built to handle that kind of traffic, so we never had to worry about the site crumbling under the load...