Unregistered users can watch most videos on the site, while registered users are permitted to upload an unlimited number of videos. Some videos are available only to users of age 18 or older (e.g. videos containing potentially offensive content). The uploading of videos containing pornography, nudity, defamation, harassment, commercial advertisements and material encouraging criminal conduct is prohibited. Related videos, determined by title and tags, appear onscreen to the right of a given video. In YouTube's second year, functions were added to enhance user ability to post video 'responses' and subscribe to content feeds.

Few statistics are publicly available regarding the number of videos on YouTube. However, in July 2006, the company revealed that more than 100 million videos were being watched every day, and 2.5 billion videos were watched in June 2006. 50,000 videos were being added per day in May 2006, and this increased to 65,000 by July. In January 2008 alone, nearly 79 million users had made over 3 billion video views.Yi-Wyn Yen (March 25, 2008). YouTube Looks For the Money Clip. Accessed March 26, 2008.

In August 2006, The Wall Street Journal published an article revealing that YouTube was hosting about 6.1 million videos (requiring about 600 terabytes of storage space), and had about 500,000 user accounts. As of April 9, 2008, a YouTube search returns about 83.4 million videos and 3.75 million user channels. It is estimated that in 2007, YouTube consumed as much bandwidth as the entire Internet in 2000, and that around 13 hours of video are uploaded every minute. In March 2008, its bandwidth costs were estimated at approximately $1 million a day.

As of Q1 2008, YouTube was not profitable, with its revenues in 2007 being noted as "not material" by Google in a regulatory filing. Exact revenue or profit numbers are not published, but a June 2008 Forbes magazine article projected the 2008 revenue at $200 million, noting progress in ad sales.Quentin Hardy and Evan Hessel: GooTube Forbes.com May 22, 2008 (Forbes Magazine June 16, 2008) At that time, the price for an ad on the YouTube home page was $175,000 per day (plus a $50,000 commitment to buy Google/YouTube ads elsewhere), and a branded channel (distinguished by a customized background) cost advertisers $200,000.

History

main: History of YouTube YouTube was founded by Chad Hurley, Steve Chen and Jawed Karim, who were all early employees of PayPal. Prior to PayPal, Hurley studied design at Indiana University of Pennsylvania. Chen and Karim studied computer science together at the University of Illinois at Urbana-Champaign.University of Illinois Department of Computer Science (2006). "YouTube: Sharing Digital Camera Videos" The domain name "YouTube.com" was activated on February 15, 2005, and the website was developed over the subsequent months. The creators offered the public a preview of the site in May 2005, six months before making its official debut.