In business, entrepreneurs are told their product will sell if they personally know 10 people who would buy it (and I don't mean obligatory family purchases or random hypothetical people or situations that could benefit!).
Angel investors and VC's also often use this to consider whether a product is worth funding.
Everyday, people are buying utility tokens at ICO for products they and no one they know will ever use, alleging hypothetical customers further along the food chain.
If you can't name 10 specific people in your life that would use the service accessible via a utility token, you shouldn't be buying the utility token. Otherwise, you are making an investment that someone will want to use that service without knowing anyone that would.
