I'm not sure what you're getting at here. Patronizing a business comes with a risk of defective products or bad service. Running a business comes with a risk of bad customers.

Doing it in a more peer to peer fashion using a website improves the flow of information about these kinds of risks, but can't eliminate them. No reasonable person would think renting out their apartment overnight to strangers is risk-free; it's just a question of whether the risk is worth the reward.