LinkedIn isn't like fishing, where you throw out a lure (your profile). It's for connecting with people you've met.
My sister just called me and told me, "I love the networking that happens automatically at a university. I just got another job offer to be a coordinator for a biodiversity project." It was from someone she knows who has worked in her professor's lab.
Meeting people face to face is still the most important aspect of networking. Then you connect with them on LinkedIn. And then when you publish on LinkedIn, they will see your thoughts.
When people know you, they will pass along opportunities that seem to suit you. They will pass you along to other people that can help you.
That's the main thing about professional networking. Gotta squeeze some palms.
This is how I have gotten ALL my clients. None of them have come to me from my website (my lure).
So, I guess this is bad news because it means you have to go out of your comfort zone.
If you have any good professional networking tips for the terminally introverted, I will pass them along to my friend, the shy internet hermit