A publicly traded company since 2006, MasterCard Worldwide is essentially owned by its numerous shareholders. Before 2006, MasterCard was a membership organization that was owned by over 25,000 financial institutions that issued the card. Now that the company is publicly traded, predictably, many of its shareholders are still banks. As of April 24, 2008, Citigroup, JP Morgan Chase & Co., and Bank of American Corp. – all well known banking names – owned a substantial share of MasterCard, in addition to a number of others, including the charitable MasterCard Foundation, which has the largest share.
As for Visa, the company was not publicly traded until 2008, and is now also owned by its shareholders. Like MasterCard, many of Visa’s shareholders are also banks or financial institutions.
When decisions need to be made in terms of changing assessment fees or other details of the way business is run, the shareholders are the ones that have the final say.