Facebook on Wednesday reported that is quarterly profit more than doubled amid big gains in ad revenues and a jump in users. Net income leapt to $791 million during the three months ended June 30 in a 138 percent increase from the $333 million made during the same period a year earlier, the worlds biggest social network said. We had a good second quarter, Facebook co-founder and chief executive Mark Zuckerberg said in the earnings release. Cashing in on the trend of Facebook members increasingly using mobile devices to connect to the social network has been seen by analysts as vital to its success.