I remember one time I went to a Filipino food place and I asked the lady if I could buy all of the remaining banana fritters (turon). She declined and said she would sell half of it to me. I asked if someone already reserved them. She answered “No. But I need to be able to sell some to my other customers when they come and ask for it.”
There’s no guarantee that she may sell all of them, but she tries to maintain good service to her customers by making available her product. She doesn’t want to make one person happy at the expense of the rest of her customers.
And I know she makes good profit anyway for taking good care of her customers.