if door-to-door salespeople must do what they do they should do it at a decent hour and whatever the hour they come, if a house has locked its front door and downstairs lights are out they should not call until someone came out just in order to try to sell them some wall's ice-cream. it's not even as if they were raising money for charity. of course one could be trying to zhuan some waikuai to support a sick and old mother at home and that sort of thing but still, what does wall's think it is doing sending salespeople out at night to hawk icecream?!