Call me naive, but somehow I expected more from the double-glazing salesman I recently invited into my home. I knew about confusing pitches, pressure tactics, cowboy installers and fly-by-night manufacturers. You do not have to do much research to appreciate that sellers of double glazing are in the hard-sell hall of fame, alongside used-car vendors and estate agents.

But I had also read the latest literature – such as Dan Pink’s book To Sell Is Human – which points to a change in the selling culture. The internet has evened up the odds. Customers are now as well, if not better, informed than sales agents. I needed new windows and I reckoned I would at least gain an insight into a more transparent era of selling.

I reckoned wrong. The national company I asked to quote first sent an old-school salesman with a box of all the worn-out tricks I thought the web was supposed to have eliminated: the “limited availability” discount; the sign-now, pay-less offer; and the “why wouldn’t you?” financing deal. He insisted I should sign up to the last, even after I had mentioned I worked for the FT and wanted more time to examine the terms. Until I made clear a local supplier had got the job, the company kept harassing me with follow-up calls.