at the scale of the largest businesses in the world, financial services are cross-sold and structurally interconnected. There is one team in a bank (it happens to be Chase, for what it is worth) attempting to capture Starbuck’s card processing business. There is another team that wants to convince Starbucks to co-brand Chase card products. These two teams can talk to each other prior to making proposals to Starbucks.

And so, without knowing anything about the payments industry, you can speculate with a very high degree of confidence that Starbucks has received a complicated spreadsheet saying what Chase will charge it for every conceivable type of credit and debit card that wants a latte. A prominent negotiated line on that spreadsheet includes, effectively, a major discount for “on us” transactions: when Chase’s left hand needs to move money from Chase’s right hand because someone wants to pay Starbucks money for their Starbucks using their Starbucks-branded money.