Which is another way of saying "Don't do anything for free" or "There's a big difference between $1 and $0." If there's a line item you're charging them, and t

Which is another way of saying "Don't do anything for free" or "There's a big difference between $1 and $0." If there's a line item you're charging them, and then a credit, it's apparent to everyone that your work has value. If it's just missing... then the value can be forgotten much more easily.