I know a certain organisation, and I won't name names, that use it as their first line of gauging how their site is performing. Completely shocking.
Them: 'Our site isn't working/slow'
Me: 'Oh? How was this diagnosed? Any url? All urls? Give me a url and some diag, what kind of connection are you on?'
Them: 'Well, I'm not sure on that, but lots of people on twitter say it is'