Really interesting… I tried to connect with someone on LinkedIn to message them but I couldn’t unless I upgraded to Premium. Tried numerous time. I finally figured out why - they are associated with an industry that LinkedIn must not like. 

 https://m.primal.net/McKG.jpg 

 I closed my account. Had a sizable network. Poof (to me at least). 

I figure - I can reach people that I need/want to without it.