There's 2 things wrong with this idea: First is that I really can't see this approach being much more successful than just being honest and saying "can you spar

There's 2 things wrong with this idea: First is that I really can't see this approach being much more successful than just being honest and saying "can you spare 5 minutes? I'll buy your coffee for the trouble." And more importantly, the overwhelming majority of consumers can't give an unbiased opinion on a business idea. Especially when you frame the question with your brother being destitute if the idea fails. 99.99% of the time, people will tell you not to do it simply because the consequences of failure are so high. Just be honest. People like free stuff. Just buy them the coffee and they'll be more than happy to listen to your idea.