I evaluate Facebook as a must-buy stocks. First of all, Facebook is one of the most popular and must-have utility for staying connected to the entire world. In addition, in spite of all the noise around the Company, Instagram has become unconditional leader in user growth (more than 1 bln users per day), as well as the most powerful app for promotion users brands from around the world. Also the advertising revenue growth trajectory for Facebook remains strong, so I don't see any reasons why you sholdn't buy Facebook's shares.
I see positive on Facebook as it reported in Q4 another solid results (above consensus): total reported revenue growth of 47% as well as operating margin growth up to 57%. The main reason is pricing increasing by 43% due to increased overall demand and improvements on mobile conversions. However, the biggest question going into FB earnings was how the recently announced News Feed (NF) changes would impact monetization.