> do you really think there are masses of people who can’t tell the difference between a single sign on service being down and individual sites being down and reporting it to downdetector?
Ahh, I see. In that case, most of DownDetectors data are from Twitter and other sources, not first party reporting, although even in the case of first party data, it is also sourced via "visits to DownDetector" which can be from a simple Google search for "is Instagram down?"
If DownDetector relied primarily on direct reporting, they'd be the last to know.
Have you never seen The Website Is Down? https://www.youtube.com/watch?v=uRGljemfwUE
The answer is: way more people than a software developer might think. Ask anyone in IT, or go to anywhere bugs are reported and read a handful.