Why is it going to be less risky for Alice? As I can see there is no software and no revenue/customers.
How are risks going to be lowered exactly so that is attractive for Alice to join?
While there is no product yet, practically this means you will put money into this. If that is the case, then relative to the amount + what your contribution worths vs Alice's, then you find how to split the percentage.
Wouldn't changing one of those "no"s to "n potential" make the venture less risky?
As you correctly point out, the business has no customers. Wouldn't it be a less risky proposition if it had commitments from potential high-value customers?
(N.B. I said "less risky", not "risk-free".)
Without more information, I think you are in better position to judge that. But, commitments without any contract is something very volatile.
You have boundless "potential". I just dreamed up an idea for a new online social networking viral game. My "potential" userbase is billions of people (my game can do accurate language auto-translations on the fly, so Chinese people can play with Russians seamlessly). My "potential" income is huge, my "research" shows that people will pay $1/mo to be a part of this game. That's BILLIONS of dollars in MONTHLY income.
Only problem is that, well, I haven't written any of the software yet (but I sketched everything out, and priced my servers, so I've "eliminated" that risk). I even checked with a bunch of people I know and confirmed that they would pay $1/mo to play this game.
There is a TON of potential here. I'll give you a 20% equity stake if you'll sign up to just write the initial code.