I read this on Paul Krugman’s blog:

I’m working at home today, waiting for the Fios [fiber-optic internet] guy. Which means that I’m probably going to drop off the face of the earth for much of today.

Which amazed me. I also read one of the comments on the post which put it in perspective:

Wow, you won a Nobel prize and you’re still stuck at home between 9 AM and 5 PM waiting for the cable guy. Glad to hear that you’re still one of the proles!— Ramesh Mantha

There might be better indicators, but poor customer service has to be one of the best tell tale signs of an oligopoly or quasi-monopoly markets. Cable companies customer service is terrible and even their wealthier customers can’t pay their way out of it.