Originally posted on Dummies.com, from his book Job Searching with Social Media For Dummies (2nd edition)

Certainly LinkedIn is a great tool to have at your job-search disposal. But not all industries are evenly represented there, and so it may not be for you. In some cases, using LinkedIn for some jobs can be a waste of time. In other cases, having a profile is essential.

It’s up to you to decide.

According to research done by Dan Zarrella, the most connected profession on LinkedIn is recruiters. Therefore, if you work (or want to work) in an industry that doesn’t rely on recruiters, you may not have strong results. However, if you know recruiters often specialize in your field, your chances of getting that unexpected phone call about an opportunity are higher.

Other research by Zoomsphere.com indicates that information technology, financial services, and retail are the top industries represented by users (apart from college students). LinkedIn’s own research puts manufacturing at No. 3 and medical (not the same as healthcare) as No. 4. If you work in one of these well-represented fields, you may have a good chance of making valuable connections.

Conduct your own research and determine if all the hype about LinkedIn applies to you.