The interesting part is that it seems like it's a flat 10%, which includes the payment processing fees:
> our payment for each purchase will be the price set by you, less ten percent (10%), unless we expressly state otherwise in writing to you. This ten percent will cover transaction costs such as payment processing fees and the cost of providing tools, features, and support described above.
This gives them an edge for cheaper subscription over the alternatives, so you can sell a $1 subscription and get $0.9.
Other similar platforms (hyper, upgrade.chat) take a fee on top of the payment processors, so you might get 0.30$ base fee + 3% from the payment processor, and an extra 3-6% from the platform itself.
That is impressive because it seems like they're eating the 30¢ from the transaction, which is annoying when dealing with microtransactions like your 1 dollar example. But I'm sure due to their market position they make back that money manifold.
> our payment for each purchase will be the price set by you, less ten percent (10%), unless we expressly state otherwise in writing to you. This ten percent will cover transaction costs such as payment processing fees and the cost of providing tools, features, and support described above.
This gives them an edge for cheaper subscription over the alternatives, so you can sell a $1 subscription and get $0.9. Other similar platforms (hyper, upgrade.chat) take a fee on top of the payment processors, so you might get 0.30$ base fee + 3% from the payment processor, and an extra 3-6% from the platform itself.