"The king of search, the king of video have gotten it together. We're going to have it our way."
Believe it or not YouTube was once a small software development/service company. Founders Chad Hurley, Steve Chen, and Jawed Karim started YouTube in February 2005. The company was acquired by Google 20 months later in a stock only transaction (October 9, 2006) valuing YouTube then at $1.65B. At the time of acquisition YouTube was reputed to have about 65 employees working in an anonymous building in San Bruno, San Franciso.
Further info
YouTube company timeline (YouTube link)
Google to Acquire YouTube, (Google link and here)
List of acquisitions by Google (wikipedia link)
(Mashable link)