percentage for revenue developer and sales man

Possible Duplicate: Forming a new software startup, how do I allocate ownership fairly?

Im a developer of mobile apps [mostly iOS, a bit of android].
I work by day on iOS development, with a few pet projects. A neighbour that is a sales guy [works for living social...]

has come to offer me a business proposition, the old lets join powers, his sales experience with my development experience.

so the idea is to offer small business with cheap quick apps, he haves some people interested [this would be a side project for him and for me, as we work on a day job already].

but the question is: how much is a normal rate on percentage for revenue for his effort and my effort?

[the time each would put to make the project work would be his calls, visits to clients, and my time developing customising the apps]

how much should i take for the development?, how much should he take for the selling?

thanks!