For me, the biggest benefit is being able to see if I know anyone at a company I'm interested in for a job, sales opportunity, conference invite, etc. and also

For me, the biggest benefit is being able to see if I know anyone at a company I'm interested in for a job, sales opportunity, conference invite, etc. and also to be able to easily connect in a professional way to people I meet without pulling them into fb (which I've basically abandoned). It might not seem like you need any of those things today, but in 5 years you might change your mind and getting that info back again without having something like LinkedIn is difficult.