Ask HN: As a developer/engineer, how do you use LinkedIn? 11 years ago
It's very effective to showcase your skills, especially that others can endorse your skills, it just gives credibility to you.
And I can see my classmates on the website too; somehow it updates me on their life which is not possible on Facebook (because you may seem boastful).
Many recruiters have been able to reach me via LinkdIn. I don't treat it as a spam. I feel proud that I don't look for jobs, jobs look for me. Someone from Singapore even contacted me via phone just because of my credentials.