Restaurants' profit margins are a lot slimmer than other types of businesses though, and in some cases (like buffets) come almost entirely from volume (i.e. 100 meals at $10/person beats 20 meals at $25/person). Depends on the type of buffet, food cost/labour, and other factors, of course.  But I do know that fat-ass customers are the worst customers at a buffet....they treat it like their variation of a sporting event.  No, they don't want a drink they have to pay for, just water with a lot of lemons...and then they dump in sugar to make "their own" lemonade ( for real, I wish I was kidding).  Then they put away plate after plate of food as fast as they can. If they can eat fast enough to have a used plate still at the table while they dig in to their next one, they love this, as they seem to think it means that they don't have to tip.  Ugh.  I still remember the Sunday brunches I used to serve at a beautiful old hotel in my city....it was a really nice, semi-formal restaurant, but for the brunch they tried to make their money through volume over quality.  The clientele was completely different.  Every fat cheapskate in the city came out of the woodwork, it was as gross as you can probably imagine...They ate like their lives literally depended on it.