> If I needed something I'd go and buy it, don't need some pushy sleazy salesman trying to trick me.
In 2021, more than $285 billion was spent on advertising in the United States. Why? Because while you might think you have an "If I needed something I'd go and buy it" mentality, the evidence has clearly shown that most people can be influenced to buy things other than what they already recognize as a need.
Door-to-door salesmen are a form of advertisement of services, and for certain industries they can be more effective than print ads, billboards, etc.
Not that I necessarily like having my day interrupted for a sales pitch; I almost invariably don't answer or turn them away.
But I'm just saying that if you have ever responded to any form of advertisement, the "If I needed something I'd go and buy it" line is probably missing the mark.