Two signals decide every status on this site.
First, visitor reports. When many independent people report the same failure in a short window, that pattern is hard to fake and quick to appear. A service needs a solid cluster of problem reports — clearly outweighing the “it works for me” signals — before we call it likely down.
Second, our own checks. Our servers request each service’s public website on a schedule. A reply in the HTTP 100–499 range counts as alive (even a 403, which usually just means a bot filter answered). Only a complete connection failure or a 5xx server error counts against a service, and even then it can only raise the status to “possible issues” on its own.
No single signal decides alone, and every status is best-effort and unofficial. For anything money-critical, the service provider’s own announcement is the final word.