Once you start doing stuff on the business end of things it's really useful:

• You've got a conf call with 3 people from a company and you want to figure out what their roles there are and other useful bits (where they studied, where they've worked, and other tidbits that can warm up a conversation).

• You want to figure out the rough size of a company you're doing a sales call with.

• You're cold calling and you want to figure out who to cold call.

• You meet a half dozen people at a networking event and would rather have their LinkedIn info than their business card for future reference.

• You want an intro to somebody who you suspect is only a contact or two away, but don't know which contact or two.

• You want to background check a potential consultant / hire and want to figure out who to run those checks by.

Before I started a company I found it pretty useless too. (All of the jobs I'd gotten had always come via intros in my offline personal network, so I never saw its utility there.)

I sit around hoping that they'll sell my email to recruiters. Y'know, for a job I actually want.

I've only had one recruiter approach me in several years on linkedin (and even he didn't have anything more interesting to sell me than DE Shaw, who had already collected my resume for their "Hey look how many people we reject" pile).

Yes. LinkedIn does most of the things it says it does for our business.

Things not to do on LinkedIn: post job ads; pay for "super" account; pay for special magic messages.

Otherwise, LinkedIn is pretty great.

If you're not actually on the business side of a business, I can see why you'd think it was useless.

Yes, actually. I've been able to reconnect with past coworkers who I otherwise would have had a hard time tracking down.

I also no longer need to maintain another resume online. It IS my online resume. And instead of saying "recommendations available on request", they're right on that same page.

Finally, it's a way to find people to work with you, if you're hiring. If you're always on the "being hired" side of the equation and never on the "hiring" side, then you won't experience that, but it's hard to find good people, and it's great to have friends-of-friends available as a resource.

As someone who's been reviewing job applications lately, I would say that LinkedIn profiles are of value. It's an additional data point in looking at somebody's job history, even if it's oftentimes redundant. I don't write off recommendations either, provided they're from the right people.

I got a lot of value out of it last winter when I was looking for a new job. It helped me learn a lot more about the companies and often the people who I was talking to. Two companies where we progressed to in-person interviews told me in advance the first names of the people who I would be talking to and I was able to figure out who they were and read their resumes before I went in. That made a huge difference for me in feeling comfortable during the interviews and helped me ask good questions pitched towards the actual interests of the interviewers.

Yes, there is a huge benefit for someone like me who has worked in many different cities. It allows me to keep in touch with people I've worked with and see where they get new positions. The key here is that it's a tool: it's only as valuable as what you put into it.

It has essentially replaced the Rolodex people used to use years ago.

If you aren't open to recruiters reaching out to you, you can make that plain and clear in your summary... "I don't speak with recruiters" or "Not looking for a position."

I know several people, as well as myself, who are head-hunted reguarily on linked in, and have seen multiple job offers come across this table. All in all, it's not bad. But more importantly, if you've been a part of a big company and worked across teams, then keeping track of all those aquaintances is valuable - they might be your 'in' to finding a job again some day. In that regard, it is near priceless.. I don't want the other software devs on my facebook, but I do want to keep in touch.

I have not. Furthermore, everyone I've ever asked has said that they also just have an account because they feel like they might need it some day. None of them ever actually use it.

Clearly it's not the case that no one gets any value from LinkedIn, as evidenced by the other commenters and the fact that they still exist. Perhaps its use falls along age or professional lines? I and my friends/contacts fall on the younger side of things; is it more prevalent among an older crowd? Among non-programmers? Among programmers at larger companies?

I do. But I run a small development shop where besides engineering I have to wear a business development hat a lot. I've made some long lasting professional relationships with partners met via linkedin groups and I've been able to get at little bit of insight into people I'm going to be meeting with who I frequently don't know.

I think its got more value for people in sales or business development then day to day engineers. But YMMV

I use LinkedIn to vet people for a mailing list I help manage. Mostly to verify that they're real people and not accounts which a spammer will use. It's not perfect as many people don't have the address they use for the mailing list aliased on their LI account.

On the other hand, every single contact I've received from recruiters has demonstrated that not a single one managed to actually READ my LinkedIn profile.

Yes, it helps find jobs through connection you didn't know you have. Try http://workastic.com for an example of automating this process.

I think that is pretty much the idea.