Naive question, how do you incentivise customers to use it and grow adoption?

My hazy understanding of the traditional credit card network businesses [1] is that a credit card network partners with a retail bank to design a credit card product offering big incentives to customers (points etc) and then gouge the merchants to pay for those customer incentives and also to pay for the network's high fees. Merchants hate it but can't really do anything about it as if they don't offer credit card payment they miss out on a huge chunk of potential business. Customers love it due to the incentives. Every now and again a huge merchant tries to launch their own competing payment system that costs them less than credit cards and they struggle to gain adoption.

Another data point, over here in Australia, an industry group formed by our major banks rolled out the New Payments Platform, in response to a strategic review by our federal reserve bank. NPP supports instant payments for low value retail transactions. It took about 6 years from design to go live, and went live in 2018. It's settled through our federal reserve bank. Wholesale payment fees charged to the banks for these transactions are not disclosed, but apparently amount to a few cents per transaction. As of 2022, 4 years after the NPP's 2018 launch, 75% of transactions and 65% of transaction value was being processed by card networks (this has been growing as cash is used less and less) while the number of card protocol transactions was still around 5-6x the number of NPP transactions [2]. This rate of adoption of NPP is relatively high, probably influenced by Australia having a small number of major retail banks who were part of the industry group designing and rolling out NPP.

[1] e.g. https://joincolossus.com/episode/rampell-visa-the-original-p... [2] https://www.rba.gov.au/publications/annual-reports/psb/2023/...