As Apple continues its push for Apple Pay across the U.S., it seems that many retailers remain skeptical about the system.

Despite the progress that they have made with Apple Pay since it launched last October, Apple is still taking an aggressive approach in their attempts to get retailers on board. The company has apparently lined up about half of the top 100 U.S. retailers to use the system in 2015.

However, many retailers are apparently still choosing to hold off on using Apple Pay, with the primary sticking points being lack of customer interest and limited access to customer data, according to Reuters:

For 28 of the retailers surveyed by Reuters, lack of access to data about customers and their buying habits is a key reason they don't accept Apple Pay. "One of the biggest concerns is data control," said Mario De Armas, senior director, international payments at the world's largest retailer, Wal-Mart Stores Inc.

Several merchants are putting their hopes on CurrentC, a payment system that offers more data to retailers while cutting out the credit card fees they would have to pay. Several merchants will not be participating in Apple Pay simply due to the contract with MCX, the company behind CurrentC, which prevents them from accepting other mobile wallet solutions.

Despite roadblocks, Apple Pay is gaining traction. In March, Apple announced that over 700,000 locations were accepting Apple Pay, and major retailers like Best Buy announcing support for the system.

Source: Reuters