how does Bundll generate revenue?, page-6

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And as the RBA considers a ban on surcharges for traditional buy now, pay later providers, Flexigroup has confirmed the service will not charge consumers or merchants. It will rely on the interchange fee from its partner Mastercard to fund a two-week interest-free period.In the cafe scenario, the interchange fee refers to the payment made by the cafe's bank to the customer's bank for the convenience of using electronic payment instead of cash.
The charge for consumer transactions can range from as little as 20 basis points to as high as 86 basis points of its value, according to Mastercard.

https://www.theage.com.au/business/companies/flexigroup-offers-buy-now-pay-later-for-your-morning-coffee-20200210-p53zg1.html