I think I might need to clarify the issue -- the problem isn't that you can't pay out to multiple people, it's that you have to pay out to each person with a separate call to the API.

In order to pay out to two separate people, you'd need to make 2 POST requests to transfers#create (at least as far as I can find in Stripe's documentation). I feel like instead of one transfer at a time, it should be both transfers at once. Say you have a cart with 5 items in it. That means 5 separate POST requests, when this seems kind of unnecessary -- why not send them and process them all at once? PayPal supports this behavior, so why not Stripe?

In other words, a request might look like

{ charges: [ {seller_id: 12, amount: 400}, {seller_id: 13, amount: 400}, {seller_id: 14, amount: 400}, {seller_id: 15, amount: 400} ] card_number: 1283123412341234 ... }