As a successful massive social network with engaged users Linked in makes me think what "engaged" truly means and how it can be measured. "X connected with Y. Z

As a successful massive social network with engaged users Linked in makes me think what "engaged" truly means and how it can be measured. "X connected with Y. Z updated his profile." was all that comes out (I am a member since its first year) and now add to it some news. Linkedin seems to be club you went with all your ex/colleagues and ex/bosses. Since no one is drunk yet, no one dances or speaks. The only valuable engagement seems to be clicking on a profile of someone. Knowing that he will see you doing this, is what stops me from clicking. Finally, people mostly pay for membership due to this instinct to see "who looked at me?".