[rmc]

if we found 100.000 paying customers and made 0.01 off each transaction that would be a 50% raise for both of us

Are you both working 'normal' salaried jobs? If you were and you were to do contracting, the usual guide of how much to charge is to double your normal rates, i.e. 100% raise.¹

So getting 100k customers/transactions per month should be seen as a big success, and hence you should be getting much more than a 50% raise.

¹: This is to cover sick days, holiday, dry spells, etc.

[GFischer]

Very true that, I hope we'll make more than that ! Thanks for the tip. Yes, we're working normal "salaried" jobs.

I expect the time investment to be less than a full time job (though at first it will probably be a lot more!) and flexibility and independence is very valuable for me.