The video-sharing website announced the milestone today, eight years after YouTube was founded as a tech startup. By 2006 YouTube was notching 100 million video views per day. Google bought it for $1.65 billion that year. Last July South Korean pop star Psy’s “Gangnam Style” video became the first to cross 1 billion views. Announcing the billion monthly user milestone today, the site seized the opportunity to pitch advertisers on its currency with “Generation C”, young adults who watch, create, and upload videos on multiple screens and share content with one another. Gen C’s viewership on smartphones is up 74% over last year, according to YouTube, which continues to back a slew of original channels as it expands.