A skilled sales rep shouldn't waste time knocking on doors. Canvassing is a different job that requires a different person. Use your best closers on qualified leads, not cold calls.
What is the value of a great salesperson, a great closer, a person who can turn a prospect into dollars and a commitment to do services? The skill of that person is wasted doing this, where they just walk along the street and they knock on some doors, and some people open the doors and they're renters and they don't want to talk to you, and you knock on some more doors, and some people are interested, but they can't talk right now. Then, boom, maybe you get someone who actually talks to you and lets you on the roof. Sometimes you knock 100 doors, you get one or two or three people that will you. Seems like a waste of their abilities, because 99 or 97 or 95 of the work that they're doing in knocking on doors is not necessarily best use of their ability.