I don't feel like I use it very much. I wonder how many of the 200M users are inactive. My guess is most of them. The top 10% is probably anyone who used LinkedIn more than a few times last year. Not to put a damper on your achievement :)

The only time I ever use it is if someone who I know is competent endorses me for something. I figure that person may be looking for a job, so I endorse them back to help them out.