In the age of texting, Instagramming, FaceTiming, and Snapchatting, it’s no secret that Millennials are obsessed with their cellphones. Mobile devices aren’t just a tool to keep in touch, they’re a way to always feel connected. It’s hard for many Millennials to remember a time when they couldn’t get their friends’ opinions or approval with the tap of a screen. Cellphones are a portal to their peers, as well as a source of endless information and entertainment. Many sleep with their cellphone, check it as soon as they wake up, and can’t even count how many times a day they glance at their phone. As a result, Millennials often consider their cellphone an extension of themselves.

To put this digital dependency into perspective, we recently surveyed 990 13-34-year-olds about how much they value their cellphone. Two-thirds said they’d be lost without their phone and more than half (54%) feel that their cellphone is a lifeline to the world around them. Millennials want to know what their network of “friends” is doing at any hour and to always have information on hand – literally. They’ve grown up using Google as a verb and are accustomed to instantaneous communication anytime and anywhere.

Their cellphones contain so much of their lives from their photos and texts to their apps and social networks. It’s no surprise then that their phones are so personal to them. According to research from JWT Intelligence, half of 18-34-year-olds say  “my phone has so much of ‘me’ in it that I feel like it’s a mini-me.” They’re also focused on customizing their phones with cases and covers that match their fashion preferences and personality. Cellphones are a key into Millennials’ lives and because of this, they want their phones to best reflect who they are.

So what does this mean for marketers? Having a mobile strategy is essential to reach Millennials. Companies can connect with consumers by offering them text message discounts or exclusive content. Youthful brands from Charlotte Russe to Claire’s are employing this strategy since they know how effective mobile messaging is among teens. Additionally, mobile games are an increasingly common way for brands to engage with consumers. Even Target chose to make a mobile game instead of a Super Bowl ad this year. Moreover, food brands and TV networks are also taking note and developing mobile games to provide more interactivity around their products. Given how much Millennials value their cellphones, we expect that having a mobile strategy will become as important for brands as having a presence on social media.