******** or without common sense?

I just received a telesales call from an Onair TV consultant informing me that I have an "older model" decoder that NEEDS to be upgraded. Upon asking him why it needs to be upgraded as the "older model" decoder is in perfect working condition his reply was something to the extent of "Because it is an older model decoder and would have to be replaced at some point in time." I told him there is nothing wrong with the current decoder after which he continued to try and push his sale and I lost my temper. Is it possible for sales people to use common sense or are they all brainwashed to keep pushing the sale until they **** people off to a point where they become rude?