I used to do door-to-door sales. I will say that most doors have a generic no soliciting sign on them and we are trained to ignore them. Otherwise wed barely be able to knock on any doors in any neighborhood (yeah thats the point har har, I get it) But honestly most of the sales came from people who had those generic signs. Probably left them there when they moved into the house etc. The signs Id pay attention to were the hand-written signs, clearly made by someone who had hit their limit with door knockers and decided to make it crystal clear with a personalized sign they took the time to write out themselves. Id leave those houses alone. Just a tip.