I joined LinkedIn in 2007. I can’t remember why. After connecting to a few dozen people, I still couldn’t fathom what the purpose of LinkedIn was, especially for an already-established professional. Yes, I knew these people, but to what end were we connecting on this site? But for some reason I stayed on for the ride, more as an experiment than in any effort to gain value. I was fascinated with the platform this company was building and wondered what its business model might be. Even after I gave up wondering, I kept adding links.