I would ask for some i.d. Personally I wouldn't give door to door salesmen the time of day, whether it's a scam or not. I thought the days of 'Good afternoon Madam, may I interest you in a vacuum cleaner?' and 'care to try our new cleaning liquid from my suitcase' in the days of internet shopping had gone but clearly not.
I don't trust door-to-door salesmen. In the words of the black guy from the film 'Love Actually' "if it's carol singers tell them to **bleep** off!'.
