Annoyingly, they removed the most useful bit (for me) several years ago in terms of getting work.

LinkedIn Answers was a bit crappy, but I used to spend quite a lot of time giving good detailed answers to people. That ended up with a few short consulting gigs that we quite fun "Could you come and sort this out for me".

They never built on LinkedIn Answers, let it stagnate and then killed it. It was much better than the stupid Groups system.