This is a really fun time waster and is certainly a novel use of online video / social marketing.
What Mattel (maker of Hot Wheels) has done is create a host of possible story directions and endings – shot each one using stop-motion video techniques, and published each one as single video entities. Choices are displayed as large buttons which enable the contestant to select which way the story will go.
I wonder if you can cheat in the YouTube version of Choose Your Own Adventure like you could in real life with the books?
