To my knowledge – and, BOY, would I like to be wrong about this – there is not a single other platform in the world that supports the by-works model that Patreon offers.
To be crystal clear, it entails:
• Patrons pledge to pay $n per work, on an ongoing basis, in advance of the work being done.
• The creator then generates works on an ad hoc basis, not to any set schedule, and each time they do, they check in with the UI to bill their patrons.
• The platform aggregates these bills, and submits them to the patrons' credit cards monthly.