Some independent sales organizations are switching from charging merchants a discount rate for their services to using a less-profitable interchange "pass-through" system, experts say, because of the complexity of interchange rates, the ready availability of rate information and the commoditization of card processing. The discount rate an agent charges a merchant typically includes interchange, plus any fees the processor and ISO add to cover such expenses as operating costs, sales support and agent compensation. "When it got so complex, … and as the merchants got savvy on the different rates that are available, the industry [began] moving toward passing through interchange at whatever [the card brands] calculated," says Donna Embry, senior vice president for Payment Alliance International, a Louisville, Ky.-based ISO. However, David Fish, senior analyst at Waltham, Mass-based Mercator Advisory Group Inc., says the tendency to offer merchants a pass-through rate has less to do with interchange complexity than with the commoditization of debit and credit card processing. "It goes along with the shift from selling on price to selling on value that is becoming more present in the consciousness of acquirers, ISOs and agents," he tells CardLine sister publication ISO&Agent Weekly. "The true differentiator isn't price. It's going to be the value-added services and the quality of service you can provide as an ISO or agent. Interchange pass-through is part of the whole phenomenon," Fish says.