The honest answer is that it depends on how many requests you accept and how busy it is where you are standing. That is not a dodge, so here is the arithmetic underneath it.
What one session pays
A client pays $19.99 for a session on demand, or $29.99 to book one up to seven days ahead. You keep 50% either way: $10.00 or $15.00. Any tip is yours in full, on top. Earnings are deposited weekly, once the client receives their images.
What a session costs you
Minutes. The session itself typically takes less than five. There is no gas to buy, no wear on your tires, and nothing to pay before you start, which is the part that separates this from driving.
Doing the sum
Plan on an estimated 3 to 4 sessions an hour. On demand that is $30 to $40 an hour before tips, and over a Saturday and a Sunday, eight hours each, $480 to $640. Booked sessions pay half again, so the same hours at $15.00 run from $720 to $960.
And if you think you can do 5 or 6 an hour, nobody is going to stop you.
The part we cannot promise
Those sessions an hour are an estimate, not a measurement. They are not an offer, and they are not a commitment to pay any amount. Nobody can tell you in advance how many people will press the button while you are standing there.
What we can tell you is the rate, which is fixed, and the time, which is short. The calculator on the sign-up page runs the sum for whichever place and however many hours you want to try.