A few years ago I had a run of cold calls from a particular double glazing company, all of which I was resoundingly rude to until I asked one caller if they did conservatories which of course they did and she proceeded to give me all sorts of details of the wonderful conservatories that they offered. After a bit of stringing along I agreed that they should send me some details in the post prior to a visit to assess my requirements.
In fairness to the girl on the other end of the line she reacted well to the start of the first line of my address; "Top Flat..." and then said she would take my number off of their list. No more calls from that company. Result.