Have not worked on the retail side since apple pay and those types of services have been introduced but can tell you that regardless of who processes the payment the seller (the retail site) gets charged for the transaction. The services that just debit your account right away (think debit card pulling straight from your account) charge less than credit cards. The reason is that embedded in a credit card transaction is credit risk, or the risk that the cardholder defaults on his bill. In the fueling industry this was a huge issue when prices went from $1.75 to over four dollars because CC companies were increasing their profits tremendously for the same amount of effort. Their defense was they were taking on more credit risk. The whole thing still lingers today as many stations charge different rates for cash transactions vs credit transactions. Cash being cheaper, but if you consider they pay as much as 3% more to accept credit cards it makes sense. Some argue that at least proprietery cards like Chevron or Shell should charge less because it is their own card don't realize that all those cards are issued and managed by third parties. Chevron and places like Lowes use Synchrony Bank while a lot of others use Citi Bank. It is a huge indusrty that a lot of people don't understand.