People adapt pretty quickly to that kind of slimy tricks. A few years ago, banks in my town would offer credit cards to everything with a pulse. They would put kiosks at the mall with sales people harassing passing customers, and they were trained to approach you exactly like this.

In a few months, everybody would know exactly what to do: Avoid eye contact, speed up when passing by, do not listen to them, do not even let them finish their sentence, and just say "No, thank you".