U.S. CEOs admit they must think about out-of-the-box models in order to grow their companies. Traditional ways no longer apply.

“The KPMG Growing Pains U.S. CEO Outlook 2018,” released Monday, reveals a conflict between what CEOs expect and the view of expectations by consumers.

The findings suggest 88% of CEOs in the consumer and retail (C&R) space believe investments made to personalize the customer experience have delivered the growth they expected, but 48% of those at retailers admit their strategies do not meet customer expectations.

The study is based on a survey of 400 U.S. CEOs, and about 1,300 total worldwide. It points to millennials as the biggest challenge for 46% of these CEOs as they find it difficult to understand their perspective, compared with older generations.

Some 46% said they find it difficult to adapt their sales and distribution models to accommodate this age group, and 44% said they have appointed or plan to appoint senior leaders who can better relate to millennials.

Despite the expectations of growth, U.S. CEOs in the consumer and retail space cite cyber-security at 25%, as well as emerging and disruptive technology at 25%, as the greatest threats to their organizations’ growth.

Operational risk followed at 21%. In order to growth their businesses, 90% of U.S. C&R CEOs said protecting customer data is one of the most important responsibilities for their organizations.

Overall, 98% see “technological disruptions” as an opportunity rather than a threat. Some 92% believe they are keeping up with innovations. Some also admit they face risks related to technology, including cyber-threats, may hinder top-line and long-term growth.

All is not lost on the millennial generation.

About 83% of U.S. CEOs are confident about the potential growth of their companies during the next three years, far more optimistic than their global counterparts, at 54%. CEOs point to M&A at 38% and strategic alliances at 23% as the top growth drivers during the next three years.