As the influence and spending power of Millennials grow, their loyalty to retailers is waning.

In just-released research from retail operations platform provider Brightpearl, researchers found that 41 percent of U.S. Millennials “admit to being less loyal to retail brands than they were a year ago.” The survey also identified “frequent turn-offs” to online shopping experiences, which includes having to register on a site to make purchases “as well as unsuitable payment and delivery options.”

Authors of the report suggest it’s a matter of not having enough patience on the part of the consumer. Derek O’Carroll, chief executive officer of Brightpearl, said retailers and brands “that sell directly to consumers but don’t offer a seamless end-to-end buying journey are setting themselves up for failure. Shoppers no longer have the patience for unsatisfactory shopping experiences — which, according to our research, are very common.”

The survey polled approximately 4,000 shoppers in the U.S. and in the U.K. Brightpearl found that “nearly one-third of shoppers, across all age ranges, are quicker to abandon a brand that doesn’t meet expectations than they were a year ago — indicating that lifetime customers are a thing of the past.”

The poll also showed that 71 percent of all respondents said if a shopping experience was poor, “they would never shop with the same online store again, while a quarter of Millennials would change where they buy goods based on their shopping experience,” authors of the report stated, adding that this sentiment suggests that brands “must work harder to encourage repeat purchases, particularly from the younger demographic.”

Of the Millennials polled, 77 percent said they were “always looking for an improved shopping experience when buying goods online.”

In regard to the fulfillment experience of online shopping, 58 percent of all respondents in the survey said they purchased goods that did not arrive when they expected. And 43 percent have had experiences where goods did not arrive at all.

Philip Graves, a consumer behavior expert, said most consumers “are psychologically attracted to what’s easy.”

“Points of friction disrupt cognitive ease,” Graves explained. “An unexpected moment of ‘pain’ in the form of an unanticipated delivery charge, the requirement to enter personal details because an instant payment method like PayPal isn’t available, or the news that delivery is going to take longer than anticipated, can shift a shopper’s mental state. A moment of cognitive dissonance arises that can be resolved most swiftly by going elsewhere or not completing the purchase. Consumer brands should be mindful of the need for a continuous focus on making their products easy to purchase because this is just as important as making them desirable.”