Justin Bieber, the 19-year-old Canadian pop star, is an internet phenomenon with 35 million Twitter followers. His first hit is the most-watched video in YouTube history.

He has upset fans on his UK tour by keeping them waiting before taking the stage, prompting some to suggest that the pressure of such extraordinary fame, experienced at such a young age, is beginning to show.

Although Justin Bieber came to fame as a musical prodigy, who found his audience through the internet, these days his power as a global brand overshadows his reputation as an artist.

Business is playing a growing part in his activities as he branches into venture capitalism by buying stakes in tech start-ups like Spotify.