(Reuters) – Shares of Facebook Inc were set to open at a record high on Thursday after a surge in mobile advertising revenue helped the worlds No. 1 social network trounce analysts expectations for quarterly profit and revenue. Up to Wednesdays close, Facebooks stock had more than quadrupled since touching a low of $17.55 in September 2012. At $100, Facebook would be valued at more than $250 billion. Facebook reported on Wednesday that its mobile advertising revenue grew 151 percent in the second quarter, accounting for about 62 percent overall ad revenue.