When LinkedIn was first set up all the recruitment firms in the world were invited to join. The employees of theses firms were then allowed to invite business owners, accountants, bankers, lawyers, directors, senior managers etc to join. You could not just join up yourself because you had to be invited by a member. This way the riffraff would be kept away.
Unfortunately within a few months every kunt and their granny could join and it seems that there are so many business directors and vice presidents of one man band businesses (in other words unemployed wankers who have registered their own company in their bedroom) that the while thing has quickly become a place where the delusional fuckwits reign.