there's the implicit agreement at the restaurant, that i give them my money, and they give me the best food they are capable of giving me, and if that food is pretty good, i might repeat the exchange in the future.
this is different for transfer of goods and services.
do you hold it against amazon if you always take the super-saver delivery option and one day it takes 5 days to get to you, and the next day it takes 8? and the week before it took 3? they say it should get to you in 5-8. but just because oftentimes they may make it in 3 doesn't mean i'm suddenly outraged when it takes 8 days again.
implicit vs explicit agreement in these matters.
and holy crap, yes, you do exist in a society in which most transactions are loosely structured contracts.
gas pump, purchase of goods, purchase of services. the pre-defined terms are "you get what you see" and we're not selling you snake oil. When i buy an apple, i trust that it's not going to poison me. I pay with money and the possibility of future money, and in return i get an apple. And typically, if the batch of apples is going to poison me, a recall... as is the case with peaches right now.
Good will isn't a cash equivalent after all.