When I was reading through this article, I thought, "How many directory telephone calls do companies really get asking them to explain there telephone tariffs?" However, I imagine they get a pretty significant number.
I used to work at an insurance agency, and people would call for an explanation of literally a one dollar increase on their bill! There are some people who like to know about every dime they're spending for a service. But they don't want to take the time to read through a long document, so they call up the company for an explanation! These are the people that I imagine call about telephone tariffs.