they are surely a pain, nowadays i just say `no thanks` before they say a word and they usually say `ok bye` but you get the odd nob who still trys to sell but gets the door in his face.
i remember once many moons ago when i was more gullable this young lady came calling asking to give to a special needs charity she was well fit and i was like `ohh come in and sit down`
ended up pledging 20 quid a month to charity
anyway the next day i phoned the bank to stop the DD
a few days later the charity phoned me up saying thanks for my generous donation and im like `anything for the kids`
pfff