Purely out of curiosity...

When you're on hold with a call center, why on Earth do they intermittently fake you out with that recorded voice that keeps telling you to "please hold" with the same exact wording every TWO MINUTES? With no useful information included like website, et al. I kind of get the recordings that tell people they can go to the website or give out hours because it might potentially thin out the queue. But the repeated useless admonishments to please hold?

It's not like you need to be told you have to wait, the elevator music is a pretty damn big clue. I can't figure out the point of this beyond irritating the people calling in further. Anyone know where this came from?