First, it keeps sending me emails about how popular my profile is. That's a lie. I click the link and it says my profile has gotten 2 views in the past 90 days.
Second, the lob listings it sends out are either jobs I've already applied for or postings that are woefully out of date. Like jobs that were posted weeks ago and have thousands of applications already. Which sucks because these days if you don't apply within 24 hours then you've missed your window.
Third, as an actual avenue for applying to a job, it's complete joke. It never works. I'm convinced if you hit the apply button on LinkedIn, absolutely nothing happens. It sends you an email that says, "you applied it a job!" What it doesn't say is that no one will see your resume and this is the last you'll ever hear about it. Thanks, LinkedIn!
Fourth, as a networking site, it's utterly useless. I send messages to contacts and never get a response. I send invites to try to connect to hiring managers and they never ever accept my invitations. Ever. I don't know if that's some sort of a power play or if they just don't check their LinkedIn page.