Credit card issuers can't make money without business, both from consumers who pay with credit and merchants who accept this form of payment as part of their POS system. Independent sales organizations, otherwise known as ISOs, are hired third-party firms or organizations that bring merchants and credit card issuers together. Credit card companies may attempt to drum up business internally through various marketing efforts or advertising campaigns. ISOs serve as another means by which to obtain a working relationship with a business that previously didn't accept credit or was only contracted with certain issuers. How ISOs get compensated for their efforts varies based on terms of agreement, but generally get paid on a percentage of sales basis. In other words, ISOs make money when the companies they sign up make money for credit card issuers.