[fusiongyro]

You're about to learn that you should absolutely never postpone figuring this out until after you go into business. There are almost certainly going to be hard feelings. If I were you, I'd split it 50/50 and call it even, unless that's really unfair to your friend somehow. Then spend tomorrow figuring out how you're going to split profits moving forward in a way that neither of you feels shafted--or you'll lose your friend or your business partner, or both.