I'm not sure I follow your example, but this isn't really comparable to factoring and Stripe doesn't get to pay out the same funds multiple times. We're shortening the time it takes a user to receive funds from a few days to a few minutes.
We charge the marketplace 1.5% of the amount paid out (with a minimum charge of $0.50, so e.g. on a $30 payout, we'll charge $0.50) and we're able to offer discounts to platforms that are operating at scale. If you'd like to discuss, feel free to reach out to me at [email protected]
During the beta, we've seen many end users choose to pay a fee when they could have waited to receive a slower payout for free. We think the value of this product is in providing choice and giving end users immediate access to their funds when they want it. The stories I've heard from Lyft drivers about the difference it makes to have this flexibility has been my favorite part of working on Instant Payouts.
Been beta testing as well -- the command line interface alone takes this up a notch over Stack Overflow, with one command you can pipe system info and error messages directly into a new issue.