Sentry open-sourced its error tool, then sold a hosted cloud version

What they ran

Sentry started as an open-source project its founders built to fix their own mistakes, says the company's about page. Over a Christmas break, while still employed at Disqus, Cramer tried charging for it. He set up a hosted cloud version with Stripe billing and launched it as a paid option. The bet was that engineers who knew Sentry from Uber or Airbnb would bring it to younger startups. Those startups would pay for hosting rather than run it themselves.

What happened

According to First Round's profile of the company, the hosted service had one paying customer on its first day and ten a few days later. Cramer says those customers came organically, at seven dollars each. Sentry later had thousands of paying customers, $600K in annual revenue and a profit. Cramer calls the plan a long-tail funnel playing out over ten years and says it worked very well.

What the account does not show

The early numbers come from the founder in an interview, so they are self-reported. The source gives no baseline and does not say what year the paid launch happened or how long the climb to $600K took. It does not show how many customers arrived through the career-move path the plan relied on. The reach of 200K organizations is a later company claim, not a result tied to this move.