Advice on hiring new sales person

[COLOR=#333333][INDENT]I know a guy who does sales and and used to be a window cleaner so has a background in both fields. I was just wondering what you guys pay for sales. Is it full commission? And if so how much? Then does the sales person get residual pay on later services from there sale down the road? I have no clue as to getting this rolling but know the value in sales for window cleaning. Thanks a lot for your input.[/INDENT]