Trust is key in building a long-lasting relationship with a significant other—and it’s just as important for a brand building a relationship with a customer.

“The Global 2017 SAP Hybris Consumer Insights Report” from SAP Hybris surveyed more than 20,000 consumers worldwide, including 1,000 consumers from the United States, about what makes or breaks a relationship with a trusted brand. Much of brand trust boils down to how brands handle consumers’ personal data.

Data breaches from companies such as Target Corp., Yahoo Inc. and Equifax Inc. have burned U.S. consumers in the past, so it’s natural shoppers are cautious about revealing too much of their personal information. While 52% of consumers are willing to share their email addresses, only 37% are willing to share their shopping history and preferences, and only 25% will give their mobile number, according to the survey.

The study suggested several techniques for online merchants to earn shopper trust from the start. First, be transparent in how the data collected will be used, and make sure it is used to benefit the shopper, says Johann Wrede, global vice president, strategic marketing for SAP Hybris, in analyzing the results. “All interactions with consumers now present brands with opportunities to collect data,” Wrede says. “Not using that data to deliver excellent services to consumers can be the undoing of a promising relationship.”

In the United States, 79% of respondents will not hesitate to “break up” with a brand if their data is used in a way other than to improve their shopping experience, according to the survey. Brands runs the risk of losing customers for good if they are not transparent about why and how they’re collecting data.

For example, if a retailer shares the collected data across international borders or sells customer data to data brokers without customer knowledge, the customers’ trust is broken and they’re likely to leave the brand. Some shoppers will give their favorite brand the benefit of the doubt the first or second time something goes amiss, but 50% of U.S. consumers will break up with a brand if the same mistake is made more than twice.

If a shopper gives up her private data, she expects to be rewarded in some way. In return for sharing information with a brand, 61% of U.S. consumers want surprises, such as freebies, coupons or event invitations, while 53% expect tailored responses to shopping queries.

Wrede suggests brands can better reward customers by building customer profiles from collected data and developing incentive programs. “It’s as simple as using collected data to create customer profiles and establishing methodology for personalizing interactions across all channels,” Wrede says. “This could translate into providing customers with recommendations based on their purchasing history or sending them small gifts on their birthday that reflects their interests.”

The more trust a shopper has in a brand, the more personal data they are willing to share. And the more she is willing to share, the more incentives and personalization brands can offer. But information cannot be earned without that initial trust. “Brands want meaningful, long-term relationships with loyal customers,” Wrede adds. “But in the digital economy, all the power rests with the consumer.”