What made Facebook's CFO to leave the company?

According to the Reuters report on Tuesday Facebook, the most popular social networking Website that has around 200 million users, announced that Gideon Yu, the company’s chief financial officer since August 2007, intends to leave the company. Thus an Internet social media company is seeking for a candidate with "public company experience."

Facebook refused to comment on whether Yu was leaving himself to get another opportunity or whether the company pushed him out. 

As company’s representatives considers, Yu has played an important role in helping Facebook to achieve financial success, building a strong finance team and establishing the core financial operations of the company. Moreover, the company succeeded in its business in spite of the economic recession owing to Yu’s work.