Ten-year-old Ryan Kaji and his family have turned videos of him playing with toys into a multimillion-dollar empire. Why do so many other kids want to watch?

When the Kaji family, of Honolulu, shared a video of their son, Ryan, with relatives, they had no idea that it would go viral – and launch a YouTube, TV and toy franchise worth millions.

Ryan Kaji is just eight years old and is one of the richest YouTubers in the world who makes $22m a year from toy reviews.

Seven-year-old YouTube star, Ryan, drew millions of views reviewing toys on YouTube. Now, Walmart is selling action figures in his likeness under the Ryan's World brand.