If I buy "unlimited salt" from a salt provider then I expect actually unlimited salt. If I buy a meal from a restaurant and that restaurant provides compliment

If I buy "unlimited salt" from a salt provider then I expect actually unlimited salt. If I buy a meal from a restaurant and that restaurant provides complimentary salt on the table I do not expect unlimited salt. Selling something as unlimited at a fixed price is clearly stupid unless there is a limit on the speed of the consumption (like the salt provider saying that you can have unlimited salt at a maximum rate of 1kg per hour or so). For something like dropbox it is even more stupid since every unit of product sold will increase their running costs.