Good personalization doesn’t require mountains of user data.

One of the most valuable strategies brands can adopt in marketing to Generation Z is to create an authentic brand and personalized marketing strategies.

Generation Z will eventually make up 40 percent of all consumers, but the desire for personalized marketing isn’t limited to young folk. In a recent study conducted through Periscope by McKinsey, 50 percent of U.S. consumers said they “really or somewhat” liked receiving personalized marketing messages.

Users most liked receiving these messages from grocery stores, restaurants/bars, and fashion retailers. A personalized marketing strategy can also be good for customer acquisition and retention: 91 percent of consumers are more likely to shop with brands who send personalized offers.

However, personalized marketing requires a delicate approach because companies need to gather data in order to optimize personalization. With the GDPR going into effect and as Facebook continues to feel the fallout of its Cambridge Analytica scandal, data handling will likely change.

This marketing strategy also requires finding ads that resonate with an audience rather than creeping that audience out. While consumers generally like receiving personalized messages or offers from stores, they do not appreciate a company texting them when they walk into that brand’s store.

This is just one example of companies poorly personalizing content. Bad personalized ads can have disastrous consequences: At best, an audience will feel uncomfortable. At worst, they’ll feel the brand has invaded their privacy and abandon the company. As many as 48 percent of users will leave your site if the personalization experience doesn’t suit them.

One study found that banks, healthcare, and tech companies employed the “creepiest” marketing strategies. Up to 71 percent of U.S. consumers worry about how companies are collecting and using their personal data. Nine out of 10 Americans worry about their online privacy and data security.

It’s not specifically personalization by location that creeps out an audience. Most web users want a choice about how they engage with brands. Consumers who see campaigns as too personal also see it as companies overstepping their boundaries and invading their privacy.

Done right, however, personalization gives brands a 10 to 30 percent revenue lift and higher customer acquisition rates.

Brands who are upfront about their data acquisition and use can boost engagement levels by up to 40 percent. A brand or site recommending consumers a link or product based on previously shared information means consumers are 40 percent more likely to engage with that content.

Personalization works best when it’s relevant and useful to consumers. Creating segmented visitor traffic and customer personas is a good way to achieve content that is relevant and useful. Building personas is an easy way to help you understand your audience without crossing the “too creepy” line.

Acquiring data doesn’t have to be difficult. Most users are less wary of sharing personal data if brands state in clear terms how they will use that data. Rather than asking users to complete a lengthy survey about site preferences, ask a question periodically. In this way, you’ll be able to better segment your audience without seeming too demanding.

Allowing your users to update their own data can help you collect data. However, this strategy only works when it’s transparent. Users need to have a clear understanding of why you need their data and how you will use it.