YouTube streamed more than 700 billion videos in 2010

"As 2010 draws to a close, it’s time to reflect on another incredible year in online video. During the last 12 months you all watched more than 700 billion YouTube videos, and uploaded more than 13 million hours of content to the site. We met a bunch of new faces (and fruits) and celebrated as new YouTube partners hit the big time with millions of views. Indeed, our partner program grew to around 15,000 participants worldwide."

Source:  YouTube blog, 22nd December 2010