I've found LinkedIn to be great for two things - becoming aware of companies/opportunities I wouldn't have heard of otherwise, and building relationships with r

I've found LinkedIn to be great for two things - becoming aware of companies/opportunities I wouldn't have heard of otherwise, and building relationships with recruiters so that when I'm ready to move on from a job, I already have ins at the companies they work with. So far, that has led to two jobs, although not my current one. But it's absolutely been worth having a profile. I mostly use it as some other people have mentioned - having notifications for messages, and ignoring the News Feed and most other features. Once a twice a year, I update my resume, and update my LinkedIn as well, which is not much extra work, but is essentially really low-cost marketing of my skills and experience. Of the messages I get, some aren't worth responding to - the "I have a job to fill using Java, and you used Java once, you should apply" type - but some are from recruiters who are willing to build a relationship and place you when the time is right, even if that isn't right away. It's often worth taking a 30 minute phone call with them, or meeting up for coffee or lunch.