Joe Sugg and Caspar Lee are two guys in their 20s who share a flat together in London. They are also members of an exclusive group of YouTube superstars breaking through into Britain's mainstream media.
Last week, it was announced that Lee and Sugg will guest-host a Radio 1 show on Sunday evenings, along with other online personalities.
So let's take a look at the two men changing the way presenters are being discovered in the UK.
Sugg told BuzzFeed he remains puzzled as to why his videos have received so much attention.
This is his first ever YouTube video, posted on 7 August 2012.
His fifth video involved his sister. It has so far been watched 2.6 million times.
Her channel focuses on lifestyle advice, but she also regularly pops up in videos by her brother, as well as her boyfriend – fellow YouTube star Alfie Deyes, aka PointlessBlog – and other members of the UK YouTube scene.
Within a year of his first video going live, Sugg was travelling the world creating more and more elaborate videos. Here he is flying to Los Angeles to spend time with Simon Cowell.
To top off a remarkable rise to fame, he has now been signed up by Sky 1 to present an online show to accompany Got to Dance.