With over 61% of people reading online reviews before making a purchase decision, it’s even more important than ever to separate the good ones from the bad. But with peer reviews and professional write-ups often having contrasting opinions, who should we trust – and why?

In an average month, people watch 6 billion hours of footage on YouTube. Research from Variety has indicated that "the five most influential figures among Americans aged 13-18 are all YouTube sensations, thoroughly eclipsing mainstream celebrities."

One in three teens claim they could make money by creating YouTube videos. The success of social media stars like Bethany Mota shows that celebrity endorsements aren't influential as they used to be. Today's teens want inspiration from cool kids who could easily be their mates.

PewDiePie is the most subscribed channel on YouTube, and its creator makes more than £2 million a year on ad sales. He's one of YouTube's elite – a new generation of hyper-influential media moguls. But why are 30 million teens watching a stranger play video games?