My grandsons will be able to recall seeing payphones in their lifetime, but the next generation most likely will not. Only in movies, photos of days gone by and museums will that generation and those that come after will they see a public telephone, a device that one deposited coins into in order to make a telephone call. To have an idea how strange that may seem to them, imagine long ago someone telling you the day would come where you would have to pay money for air?
Closer inspection of the sign shows that if you buy gasoline, California law states that you are entitled to free air and water. You just have to go inside and state your case to the cashier. Otherwise, pay a dollar.