this is absolutely true and any product or service that requires sending people to knock on doors in order to sell it is by definition not worth buying, because

this is absolutely true and any product or service that requires sending people to knock on doors in order to sell it is by definition not worth buying, because if it were, they'd sell plenty using regular advertising. anyone that comes to my house to sell something is automatically a scam in my perspective and it is usually those fake electric company / gas people, though sometimes someone offering to redo my driveway.