A system always checking to see if "Internet" is up is different than "I think something is wrong, let me check".

Yeah. I've had ping tests fail in false-positive and false-negative scenarios and the take away isn't that there IS a problem, but rather an investigation should probably take place. I don't think anybody here is trying to argue that pings (or DNS lookups) are an infallible reachability index for "the internet".

When it comes to customers, ping tests are a non-issue because the complaint is normally that YouTube, Facebook, or whatever service isn't available and therefore the "internet is down". At some point you have to weight the cost/benefit of explaining to customers that the internet is a large collection of interconnected networks and not some "cloud" that we tap into. It is a series of tubes after all.

K