Restaurants do care if they deny reservations to non-paying customers and then have empty tables because your business didn't sell as much as usual. They also

Restaurants do care if they deny reservations to non-paying customers and then have empty tables because your business didn't sell as much as usual. They also care about alienating customers who are told, "We don't have any free reservations available, but some are available for an extra charge." Very likely, if they found out what you were doing, they would put you out of business whether you were hurting them or not, just to prevent their patrons from ever facing that choice. Like I said, the greatest proof that restaurants don't want their patrons paying for reservations is that they don't do it. They already have what they need: a way of recording reservations and a maitre d' with knowledge of their business and a triple-digit IQ. They know there's demand: many people already try to get a table on a busy night by slipping the maitre d' some cash. If they wanted in on it, they'd already be in on it, and you'd be stuck trying to convince a restaurant to hand over control of a simple, vital, near-zero-cost part of their business to a third party for no gain. I maintain that you could only survive as a parasite by avoiding notice and/or paying off the right people.