What? You’re not on LinkedIn yet? What are you waiting for? These seven reasons outline why you should be on the social networking site.

1. Because That’s Where The People Are. LinkedIn is the number one social network for professionals — and, arguably, the most important website for jobseekers — with more than 150 million members worldwide. Not only are people you know already on the site, but so are people you should get to know — recruiters, hiring managers, and your future co-workers.
2. To “Dig Your Well Before You’re Thirsty.” In his book of the same name, author Harvey Mackay advocates building your network before you need it — and joining LinkedIn now gives you time to build your network of connections.
3. To Strengthen Your Offline Network. LinkedIn helps you keep track of people you know “in real life” — what they are doing, where they work now, and who they know.
4. To Reconnect With Former Co-Workers. Sometimes it’s hard to stay in touch with the people you used to work with — making it difficult to find them when you need them (say, to use as a reference in your job search). LinkedIn allows you to search contacts by employer, so anyone who listed that company in their profile will be found in the search.
5. Because You Can Establish Yourself as an Expert. One of the ways to be seen as a thought leader in your industry is to increase your visibility. One way to do this is to actively participate in Groups related to your job, and also to respond to questions on LinkedIn’s “Answers” forums. Anytime you post in Groups or answer questions, these updates will be available in your profile, so people looking for you can see that you are actively engaged in this online community.
6. To Be Found as a Passive Candidate. Having a robust LinkedIn profile — filled with your accomplishments and strong keywords — will lead prospective employers to you, even if you are not actively looking for a job. Recruiters especially are always searching LinkedIn to find candidates to match their search assignments.
7. Because Your Presence on LinkedIn Can Help You Be Found Elsewhere Online. It’s common practice for hiring managers and recruiters to “Google” job candidates, and your LinkedIn profile will likely appear high up in their Google search results. A strong LinkedIn profile can enhance your candidacy, especially if you have a solid network of contacts, at least a few Recommendations, and you’ve supplemented the basic profile information with things like lists of your certifications, languages you speak, SlideShare presentations, honors and awards, and/or your professional portfolio.