Apple Pay is a mobile payment and digital wallet service that allows people to make payments with their iPhone 6, iPhone 6 Plus, Apple Watch-compatible devices (iPhone 5 and later models), iPad Air 2 and iPad Mini 3. Currently, Apple Pay works with Visa, MasterCard and American Express. Discover recently announced it will join in the fall.

Although Bailey said that the number of retail locations accepting Apple Pay will surpass one million next month, adoption is still a challenge for the company. Fewer than a quarter of the country's top 100 U.S. retailers accept Apple Pay and about two-thirds of the chains said they will not accept it this year, according to a Reuters survey published Friday. Cost, insufficient customer demand and a lack of access to the data generated by Apple Pay transactions were the biggest reasons retailers in the survey said they won't accept Apple Pay.

Bailey said that Apple is working with Square to help more small businesses accept Apple Pay and will launch a new Square reader this fall.

Apple Pay, of course, is not the only player in mobile payments. Just last month, Google unveiled Android Pay, which allows credit, debit, prepaid and small business cardholders to use their Android devices to make purchases. And later this year, Merchant Customer Exchange plans to roll out a competing mobile payment network called CurrentC, which will offer features similar to Apple Pay, including tokenized transactions and the ability to use merchant retail cards, loyalty programs and coupons, according to MCX. MCX's owner-members operate more than 110,000 locations and process more than $1 trillion in annual payments.

More than 150 credit unions now use Apple Pay in the United States, and Apple Pay will launch in the United Kingdom next month, where it will support more than 70% of the debit and credit cards there, Bailey said.