As the range of digital channels has proliferated, so too has the number of channels customers use to interact with companies, with a growing number of consumers tapping texts, social media, email, online chats and mobile apps to get help. But, as it turns out, the channels customers select to engage companies depends on a variety of factors, including age and the nature of the request.

2016 research from Dimension Data illustrates some of these differences between how consumers of different ages contact customer service. For instance, while those between under 35 prefer digital customer service channels like social media and mobile apps, older users rely more on analog channels like the telephone or more “traditional” digital tools like email.

How customers reach out is also a function of the nature of their request. According to August 2016 research from The Northridge Group, phone calls remain the most popular channel for billing and payment questions and for resolving problems, with more than 50% mentioning the channel as their preferred method. Meanwhile, for consumers who wanted to make a comment or suggestion, email was more popular than phone calls, mentioned by 35% of respondents.

For marketers hoping to reassess which customer service channels are most important, the short answer appears to be “all of them,” which means utilizing as many as possible particularly when targeting millennials. This point is further driven home by additional data The Northridge Group’s study. Four in 10 millennials indicated they would switch channels if their customer service issue wasn’t addressed within 60 minutes, higher than any other age group studied.