I personally feel the approach recommended here is unethical. However striking up conversations with random people does have other (different) benefits; 1/ The

I personally feel the approach recommended here is unethical. However striking up conversations with random people does have other (different) benefits; 1/ The act of regularly practicing your pitch helps you find holes in the idea - often indirectly. Sometimes people say something off-topic that can make you think "damn - I should have considered that" 2/ Due to the "Faster Horse" effect you're unlikely to get decent product insights - especially with some types of consumer products. However, what you can do is get very useful insights into the person's pain points: "Why are they too busy for a competitors product?"; "Does the fact they have family abroad suggest previously unconsidered business models?" etc 3/ It helps you become more confident - provided you don't lie. Presumably if you end up only being confident when you lie then before you know what happened you'll become a scam artist!