akmac - 7:30 pm on Jun 29, 2010 (gmt 0)
First, it is his business. Unless he'd like to propose a mutually beneficial partnership, the expenses related to the operation of his business remain his own.
That said, don't cut off your nose to spite your face. If a 40% "profit" would be entirely eaten up by your commission then your commission structure needs to be reworked. Specifically:
any extra revenue is paid at the highest tier, 40%
seems to be the sticking point.
It's in neither of your best interests to continue the status quo, as the current commission structure is effectively strangling new business for you both.
Without further details regarding what constitutes "extra revenue" I would propose that the extra revenue referenced above be split between you at a mutually agreed upon rate, with his take being larger than yours. The reason for this is that it's absolutely necessary that the owner remains motivated to grow his business.
I know that you feel you've already chipped in, but you do not have ownership of the previous increases-even though you generated them. HE does, because HE was smart enough to hire you. It is in your best interests to continue making him feel smart. I would tread carefully in these negotiations-as you risk poisoning a relationship that has been profitable for you both, and can continue to be with a bit of compromise.