A recent study published by market research company Phoenix Marketing International found that 47 percent of all Apple Pay users shopping in a participating store were not able to use Apple Pay to complete a transaction at least once.

The finding reflects one of the biggest stumbling blocks that Apple Pay and its competitors face in trying to get people to adopt mobile payments—the fact that no payment platform can control the experience a customer has when they walk into a brick-and-mortar store.

Phoenix surveyed 3,000 people about their smartphone shopping habits. 523 of those were iPhone 6 users (currently the only model on which Apple Pay works), 350 were Apple Pay adopters (linking a card to the service), and 302 had made a purchase at least once in the four months since Apple Pay was introduced in late October.

The survey asked iPhone users about what kinds of problems, if any, users had experienced at checkout while using Apple Pay. 27 percent said that the terminal didn't work during the transaction, and 48 percent said that at least once it took too long to record a transaction. 42 percent of Apple Pay users said that they ran into a situation where the cashier or sales agent was unable to help them when they had a problem.

The top three retailers where Apple Pay users reported making in-store purchases were the Apple Store, McDonald's, and Macy's. (Our own edit staff has had trouble trying to make purchases with Apple Pay in the Apple store.)

Tim Sloane, an analyst with the Mercator Advisory Group, said that those numbers aren't great news for Apple, but they aren't great news for any other mobile payments platform (like Google Wallet/Android Pay or the upcoming Samsung Pay platform) either. “Even with a plastic card, turn downs at the POS [Point of Sale] will drive the consumer to a different card,” Sloane wrote to Ars. “It is hard enough to get a consumer to remember to use Apple Pay instead of the card. Add to that the fact that when [consumers] do remember it may not work, and Apple has a problem, not that Apple can do anything about it!”

“Acceptance is a bank and network issue, not an Apple issue,” Sloane added.

The lack of control over the user experience may turn some potential Apple Pay customers away, but Phoenix's survey showed that Apple was at least successful in getting early adopters to use its payments platform, estimating that 12.2 million iPhone 6 owners have used Apple Pay at least once in the four months ending February 28.

And, despite suffering glitches at the cash register, “Apple Pay users report a high level of convenience at check-out,” Phoenix wrote.

The researchers also asked Apple Pay users why they used the platform. 74 percent agreed that the process is “Faster than selecting a card from your physical wallet, swiping the card, and getting a paper receipt.” 58 percent said that they thought Apple Pay was “safer than swiping a magnetic stripe payment card at the register.” 59 percent of Apple Pay users even confessed that they use Apple Pay because it makes them look “stylish and cool.”

But Phoenix also found that a large number of Apple Pay users already had some experience with mobile payments before, so the hard work in convincing mobile payments novices to use Apple Pay is still ahead. 41 percent of Apple Pay users reported that they also used the Starbucks mobile app.

Every party needs a disinterested party

Still, the biggest issue is getting merchants to adopt NFC terminals and train their staff accordingly, but the reluctance to do that has been dramatic. “Apple is gradually adding more merchants, but [it] definitely needs to break into more large merchants to really take off,” Shirley Inscoe, a senior analyst at Aite Group, told Ars. “This is a barrier due to MCX and the merchants’ desire to avoid Visa fees.”

MCX refers to Merchant Customer Exchange, an alliance of big-name retailers like CVS, Bed Bath & Beyond, Wal-Mart, Old Navy, Kohl's, and more. MCX caused controversy last year when it instructed all of its retailers to disable any Near Field Communication (NFC) readers in their checkout registers, blocking not only Apple Pay transactions, but transactions using Google Wallet and (the now defunct) Softcard.

MCX promised customers that it would have its own, better mobile payments scheme called CurrentC that would only accept debit cards (so retailers could avoid pesky credit card fees) and would work by scanning a QR code sent to the customer's phone. CurrentC quickly became the butt of Internet derision when its mailing list was hacked and the e-mail addresses of its potential customers were leaked.

Phoenix asked its 3,000 respondents about CurrentC as well. “When asked to choose between Apple Pay and CurrentC, Apple Pay has the decided advantage over CurrentC,” Phoenix researchers wrote, saying that Apple Pay had a 6:1 advantage among iPhone users. That number dropped to 2:1 among all smartphone users.

Update 4/1/2015: A spokesperson for MCX e-mailed a response to Ars Technica saying "MCX is aggressively building its mobile payment and commerce network and is excited to launch later this year. We are enthusiastic about the opportunity in front of us and are backed by the confidence of our many merchant owners and partners in this venture." The spokesperson added that CurrentC will evolve based on user experience and feedback. "We expect to launch an early-stage version of the CurrentC app in mid-2015, in a mid-sized market, to help us develop and enhance functionality and user experience."

Credit limitless

One of the most interesting facets of the Apple Pay ecosystem is Apple's relationship with banks. It's widely reported that most banks are paying Apple a small percentage for each transaction that occurs over the platform, possibly due to the fact that Apple Pay uses tokenization, a scheme that makes it significantly more difficult for identity thieves to steal credit card numbers during a transaction. But it's also recently been reported that fraud via Apple Pay occurs at a higher rate than fraud via magnetic stripe cards because banks have weak verification processes and can't tell if a person uploading a card on an Apple Pay account is real or just using a stolen identity.

One piece to the puzzle that might keep banks paying into Apple's platform is that customers seem to use credit cards more often on Apple Pay. According to Phoenix, 82 percent of Apple Pay users linked a credit card to their accounts, and 53 percent linked a debit card. “Among those that linked both a credit and a debit card to Apple Pay, 67 percent reported that the credit card was the first-card—thus becoming the default card.” Phoenix wrote. “56 percent rarely or never change the default when making a purchase.”

That behavior is interesting on a number of levels, not least because when a credit card is used, banks get higher interchange fees and consumers are better protected from fraud by federal credit card regulations. The only party losing out is the retailers. (Well, until they pass the costs back on to the customer). “Banks always prefer cardholders utilize credit for the higher interchange the banks receive,” Sloane wrote to Ars. “Consumers often pick credit over debit for higher risk transactions since credit has greater protections under [Regulation] Z. Mercator consumer data indicates that many smartphone owners are not confident that the smartphone is safe for payments, which may incline them to enable credit cards before debit cards (or maybe it’s for the rewards!).”

But as consumers keep choosing credit cards for their Apple Pay purchases, it becomes less likely that retailers will find it in their own best interest to support Apple's platform and devote resources to maintaining a smooth checkout process for Apple Pay users, even if checkout terminals are equipped with NFC-reading technology.