When someone puts something that isn't real or does something really moronic on a website in hopes of getting a high rating and/or lots of thumbs up.
Urban Dictionray:shark porn?dayturnal??macaroni and sneeze??? What the fuck this ain't Youtube!!!!

A Local News station: Give our Facebook page 25,000 thumbs and we'll donate $25,000 to the humane society. My reaction: what a bunch of fame whores. Don't they realize this ain't Youtube???
by Hunterinabox August 6, 2011
Get the This Ain't Youtube mug.