[d0m]

I would still go 50/50 because at that point, after one year of the prototype who generated revenue, you could go the "solo founder" let's hire employee route.

The thing is.. look at the stats, most startups fail. Having an equility split really make both co-founders committed and started in the right direction, which goes a long way about making the startup succeed. How would you feel about starting a startup where you don't have equal split with the person who'll spend all your days with?

If you ask that question, I think it's because you haven't found the right co-founder. I.e. Let's say you have a selling book website for a year with some revenue, and then you can have Stephen King joins you as co-founder. Would you hesitate to give him 50 if he fits the role? Now, obviously you don't have a book business and this is not Stephen King.. but still, the idea applies. If you think it's not worth 50, it probably isn't and you should try to find someone else. Otherwise both party will be unhappy. Your co-founder won't feel equal and you'll find that you gave too much.

That's my 2c (and to explain a bit the lesson from OP)