
WhatsApp —
In an attempt to dominate messaging online, Facebook acquired WhatsApp for the record sum of $19 billion. The five-year old app had 450 million users at the time of the acquisition in February 2014, adding a million users every day.

Oculus VR —
Oculus makes a virtual reality headset which covers users' eyes and immerses them in a virtual environment that responds to their head movements. Facebook said its focus is on investing in the product for the future.

Instagram —
Facebook bought the photo-sharing network Instagram for $1 billion in 2012 with a combination of cash and stock. "Providing the best photo sharing experience is one reason why so many people love Facebook and we knew it would be worth bringing these two companies together," Mark Zuckerberg said about the purchase.

Gowalla —
Facebook acquired location sharing service Gowalla for an undisclosed sum in 2011. The purchase enabled Facebook users to share their location more often. Its features were integrated into Facebook's Timeline, which was launched at around the same time.

Parakey —
When Facebook bought Parakey in 2007 for an undisclosed sum, it was its first big acquisition. Facebook was actually buying the brains behind the startup -- Blake Ross and Joe Hewitt, the co-founders of Mozilla Firefox, an open-source web browser. Ross and Hewitt joined Facebook's team to work on the development of the network.

ConnectU —
In a deal that inspired the 2010 Oscar-nominated drama "The Social Network," Facebook agreed to acquire ConnectU from the Winklevoss brothers after a court settlement under which Facebook bought the rival networking site for cash and a share in Facebook stock.


