Oh that's pretty cool. It looks like there are no fees for the service (at least for now), where Venmo has a 1.75% fee ($0.25 min $25 max) and Cash App has a 0.5%-1.75% fee ($0.25 min) for the same instant withdrawal service.
I suspect the personal side of it will remain free. It's a gateway drug to having your card on file. Then there is less friction when you see something on marketplace you want. They can recover money on the marketplace side of things.