Great ideas!! I think that your third suggestion would keep the customer journey really simple (and therefore encourage usage). Card companies do only see the total transaction amount and even retailers can't track customer behaviour easily due to customers using different cards/payment methods when they shop. Loyalty programmes are what allow retailers to track the exact products that customers purchase and they are increasingly offering bespoke deals based on specific information (although it is normally a 10% discount etc. given if a customer hasn't bought a particular product/brand in a while instead of an attempt to change customer behaviour in regards to health etc.) . If you had a partnership with a retailer then you could collect the information and support a 'healthy food loyalty programme' whereby customers receive more points/cashback for healthier options - With technology such as Apple Pay, payment could all be linked to an app where you could also track your eating habits? I'm guessing retailers could be in support of this seeing that people are now increasingly health-conscious, a customer-caring loyalty programme would provide a point of differentiation against competition and it would keep spend within their store? Customers would also most likely enjoy the gamification of eating healthily if the app were community-driven as well as the financial rewards from a retail partnership?