Meet Jack & Jack - the massively Vine-famous teen heartthrobs with millions of devoted fans

More and more social media celebrities are striving to break into the mainstream - some more successfully than others.

But two best friends who found success online have seamlessly turned their Vine fame into a chart-topping music career - even though they're not signed to a record label and most people over the age of 22 have never heard of them.

Jack Johnson, 19, and Jack Gilinski, 18, hail from Omaha, Nebraska, and have been friends since kindergarten. After a short-lived YouTube stint in high school, they discovered Vine and started posting under the username "Jack & Jack" in 2013.

Their funny Vine videos have helped them amass a following of  5.6 million. They often collaborate with fellow Vine celebs like Nash Grier.

Jack & Jack also started posting on YouTube again and have amassed 952,000 followers on their channel. Their YouTube channel now mainly functions as the digital home base for their pop-rap music career, hosting all of their videos.

About that music career: it's taking off.

Jack & Jack's third single, "Wild Life," hit number one on the Billboard Twitter Top Tracks chart.  "Like That," their single with Skate, hit number three, and their current single, "Groove," is at number seven, even though it won't be available for purchase until May 30. 

The teens' music has also appeared on the digital R&B and hip hop charts, most notably when "Wild Life" hit number four in August 2014.

Now, they're living in LA and focusing mostly on their music career while also posting to Vine on occasion. They also toured the United States with DigiTour Media in 2014, and they're touring again this summer.

Jack & Jack don't have a traditional record label, but they're signed with Fullscreen, a global media company with about 70,000 creators in its network, including Grace Helbig and the Fine Brothers. We met them at an event hosted by Fullscreen last month, then asked them a few questions over email. Here are their answers.

Business Insider: Did you always want to be musicians, even before the Vine fame?

Jack & Jack: We always loved music and writing but would have never thought to go in the direction of pursuing music because it is such a difficult market to break into. Vine gave us a platform and most importantly, a fan base. When we realized the enormity of the fan base and how supportive they are, we decided to take a shot at really pursuing our music. 

BI: What is your songwriting process like? 

J&J: Develop the concept, then write hook around the concept, then go deep into detail with the verses. 

BI: Where do you find inspiration? 

J&J: Other artists, life, people we look up to, and of course our fans and the stories we learn about their lives. 

BI: While you're writing a song or making a Vine, how do the two of you balance things?  Does one person come up with the ideas more and another person specialize in execution? 

J&J: We have a very fluid working relationship and really inspire and bring out the very best in each other creatively. Part of that comes from having such a long history together. Most people are so surprised when they first meet us in a working situation that we actually finish each other's sentences. We know how lucky we are to have this kind of friendship that has also become a great partnership creatively.  

BI: How do you divide responsibilities? 

J&J: We both have different strengths and weaknesses. We don't divide so much as work it out together and make sure we really have fun whatever it is that we have to get done.  

BI: Are you still adamant about staying independent instead of signing with a label? 

J&J: We are glad we've stayed independent as long as we have. It's allowed us to grow and learn about the entire process of putting out music from beginning to end.  We have a lot to learn and the music business is changing a lot. There are a lot of advantages to staying independent but when we see friends like Shawn Mendes, there are advantages in being with a label too. Labels have access to radio and strategic marketing that we don't have. We are doing great now but we don't want to shut the door on a potentially good partnership, if it came along. 

BI: Your music tops the charts, but the two of you aren't household names yet. Does this bother you or do you think it's cool to be massively popular but still somehow under the radar? 

J&J: The best is yet to come. Our fans are our best motivators to make better music. We just want to be as good as we can for them and not let them down. If we become household names it will be because we worked hard to find our sound and, the fans who have sustained us through the journey.  They are as much a part of our success as we are. We have the passion, drive and the best supporters anyone could ask for. If that gets us to a place where we are a household name, that would be great, but our goal is to make the best music we can that feels right for us.  

BI: Who are some of your idols? 

 J&J: Let's start with our fans. They just put a smile on our face every time. Then, of course our parents and families for being so supportive.  We love artists like Justin Timberlake who are musical acts but also act and do comedy.

BI: Who do you look up to in terms of music career?

J&J: Artists who stay relevant by being able to adapt over time, yet still being true to who they are.   Bruce Springsteen, Lil Wayne and a big group of artists in between come to mind. 

BI: Who are some of the other crossover social media stars you look up to who have found success in mainstream media like the radio, TV and film?

J&J: Shawn Mendes is the one that comes to mind right away, and has done a great job of crossing over.