Many employers now are vetting candidates using social media, so having a half-done profile basically is akin to showing up to a job interview in sweat pants.
Here are the top reasons you should consider LinkedIn as much a valid career tool as your résumé:
1.) Establish your online presence. Nowadays, if your name doesn't pop up on any online searches, it has become almost a bad thing. This might lead an employer to think if a candidate hasn't done anything to establish and maintain an online presence, the prospective employee likely is a non-entity with virtually no accomplishments, affiliations, or leadership qualities. It also indirectly shows a lack of career drive. By jumping in, you can help dictate what is published about you.
2.) Collect recommendations. Instead of heaping on a pile of letters of recommendations into an application, ask colleagues, supervisors, clients, and people who are familiar with your abilities in the workplace to write a testimonial. It can accomplish the same thing, and it also provides that first-blush impression of you as a person. Plus, it consolidates this information in one place, so you aren't scrambling for recommendations at the last minute. Be specific -- when asking someone to write your positive work attributes, make sure you strategically ask them to talk about one specific aspect of what you have to offer. By spreading out your attributes among several people, you allow for a wider scope of who you are to prospective employers, but be careful about "trading" recommendations with your friends. Employers can spot these a mile away, and essentially, these become worthless if it is simply a "scratch my back/scratch your back" exchange.
3.) Establish yourself as a subject matter expert. Some fields require pretty specific knowledge. The question-and-answer section of LinkedIn can help you establish yourself as a subject matter expert and gain user votes for your expertise along the way. Find the appropriate categories where you feel that you can contribute intelligently, and answer questions selflessly. Don't try to insert any plugs or sales pitches to try and direct readers to your site -- that's the fastest way to get blacklisted.
4.) Find jobs. Many employers relish the aspect of having the "six degrees of separation" factor with LinkedIn and are starting to post only jobs on this site. The company hiring manager or human resource manager can find a linkable trail to how you might be connected to someone inside the company should you apply.
5.) Find people and become connected. Conversely, if you find a position of interest, remember that people pave the way to jobs. Identify a job opening with a company, then jump onto LinkedIn to see if you are connected to someone at that organization where you can find out additional information about the opening. Be careful about using people -- no one likes being a stepping stone. Cultivating those relationships can pay off when a job opens up there, and you will have established an internal advocate.
6.) Join networking groups. A group virtually exists for everyone on LinkedIn, and by connecting to the right "packs" of connections or the same industry, you can stay abreast of current issues and trends that can keep your industry-specific knowledge honed. You also can gain influence while enhancing your online profile by participating in discussions and also answering some of the questions (see No. 3).
7.) Use LinkedIn to gather business intelligence. This online tool doesn't need to be just for looking for jobs. You can use this site as a way to gather information on competitors, which may help you in your current position. This doesn't mean trade secrets; this usually means gaining enough information to obtain competitive profiles of other companies.
8.) Show traction through regular updates. LinkedIn allows users to add an update along the lines of Twitter and Facebook. Keep it business-like. Adding tidbits about a recent conference you attended or a presentation you gave can provide a visitor to your profile a sense of your career traction moving forward.
By understanding these points, you will be able to leverage your online presence to augment your credentials and stand out from the crowd.