Click the button at the top taskbar. -> Contacts - Details tab -> Salesman tab.
Purpose of the Salesman tab:
Salesman tab is used to set a default lead cost and default commission values for the selected salesman. Note: those values take priority over global lead cost and commission values.
What you see in the Salesman tab:
Default Lead Cost % - this value takes priority for the selected salesman over global lead cost.
Default Commission % - this value takes priority for the selected salesman over global Salesman commission.
How to use the Salesman tab:
Change the selected salesman default lead cost and commission.