> During that period, there were 24,826 first time visitors to any of our sites who we could identify as having first gotten to us via Hacker News (in all, we received more like 105,000 unique visitors from Hacker News, but many of those were repeat visitors). 97 of those visitors signed up, with more than 85% of them electing the free plan.

Left unsaid: how many of the 105,000 unique HN visitors are customers?

Also left unsaid (but harder to quantify): how many of those 105,000 HN visitors are influencers who have referred 37 Signal products to others? (FWIW, I know of at least half a dozen teams who've signed up for BaseCamp paid accounts as a result of my recommendation.)

[ UPDATE: In response to subsequent comments below, I've created a poll here: http://news.ycombinator.com/item?id=3680400 ]