Disney is adding a sizzling new entity to its magic kingdom: a leading network on YouTube. In a $500 million deal that validates the mainstream influence of homespun content creation, Disney has signed on to purchase Maker Studios — one of the biggest networks on the Google-owned, video-sharing site. All told, Disney could cough up an additional $450 million to Maker if the network reaches certain growth milestones by the time the deal closes in Disney’s third fiscal quarter, reports The New York Times.