No, their entire model is based on the assumption that users could extract maximum value from the buffet (eating everything) but typically don't (have a normal-

No, their entire model is based on the assumption that users could extract maximum value from the buffet (eating everything) but typically don't (have a normal- to large-sized meal, the supply cost of which is obviously far less than what the customer pays to get in). The parent commenter's point is that many businesses are run this way (eg. the gym is not equipped for 100% of subscribers to go to the gym every day, just as the buffet is not equipped for 100% of customers to eat a huge amount).