Why do people feel duped by YouTube blogger Zoella's book?

Last week the YouTube blogger Zoella admitted that her hit debut novel, Girl Online, was written with "help" from her publisher.

In a post shared on Twitter, Zoella, or Zoe Sugg, said: "Of course I was going to have help from Penguin's editorial team in telling my story."

While she joins a huge host of authors who have received aid from so-called ghost writers, the revelation was met by many with disapproval.

The BBC's arts editor Will Gompertz reflects on why, in a world that focuses on the individual, some of Zoella's fans felt duped by their idol.