Mobile advertising is a joke. If you used the site on a mobile device you should understand that they are barely seen and no one cares!!! E gift is also a joke and will only be used by your teeny boppers who live on the site and have to ask their parents for money (no purchasing power). What is to stop Twitter (the preferred social networking site) from doing the same thing? Tell me, did Google or Apple ever trade at a 140 P/E?
Mobile earnings are real. Check the earnings report. If u don't believe the numbers contact the SEC. Gifting probably not a big deal, but teens DO have major purchasing power. They buy cell phones, music, clothes. Their income is the best kind of consumer income. It's expendable. As for competition, Facebook could lose, but they are less vulnerable now because they've passed the fad stage. And they own Instagram which has its own buzz. Forward PE is 43. Nobody cares about present PE.