LinkedIn, owned by Microsoft, hosts the profiles of nearly 800 million people in over 200 countries and 2.8 million locales -- and up to 47% of them are active users. LinkedIn reports 97 million monthly unique visitors worldwide, 57% of whom log on via mobile devices. In the U.S., 27% of adults (180+ million users) have LinkedIn profiles. Over 30 million companies have company pages on LinkedIn. Furthermore, according to LinkedIn, there are executives...