I think what the OP is trying to say with the quote with traditional volume discounts, you're always getting some additional money per additional unit. With an

I think what the OP is trying to say with the quote with traditional volume discounts, you're always getting some additional money per additional unit. With an "unlimited" license, you don't add any additional revenue while the customer adds people. After a certain point with a site license, everything is "free" and that could be bad for the person selling (no additional revenue, increased support costs, etc)