This is the fourth part in our ongoing series on recommended sourcing techniques. For other parts of the series, please view:

#1 Internal Promotions

#2 Referrals

#3 Job Boards

This is the place the pros turn for talent. LinkedIn can be an extremely powerful tool in an experienced hand. With amazing search technology and a reach that covers a good portion of the western working world, professional recruiters have turned much of their sourcing efforts to pinpointing the perfect candidate on the web’s largest professional network.

Due to it’s vast reach and the longterm nature of its profiles, LinkedIn is also one of the best ways to effectively source passive candidates. Unlike job boards and other methods, candidates on LinkedIn aren’t necessarily actively seeking new employment. At least, they don’t know they are until you make them a better offer. It only makes sense that if you’re looking for candidates with the perfect skillset, poaching the already polished talent from your direct competittors is a good place to start.

LinkedIn’s greatest strengths, however, are also their greatest weaknesses. With 300 million people, you have every possible player you need for your team. The downside—there’s 300 million people to sort through! Even a few hundred from the job boards can be mindnumbing. Unless you’re an expert at sourcing, it can be difficult and time consuming to find the right candidates. You’ll almost certainly need a heftily upgraded account that allows for more refined searches.

And don't forget—you're not the only one sourcing on LinkedIn. Eeeeeeveryone's on there, and the competition is fierce. You're not only competing with other employers, you're competing with the top recruiting agencies in the world. If you like your chances against the Heidrick & Struggles of the world, then be my guest.

When you find a good candidate, they've probably already been hit up with job offers 20 or 30 times...just this morning. We recently interviewed a top programmer for one of our open tech positions, and he estimated that he has probably received roughly 10,000 InMails and emails from various companies and recruiting agencies over the last 5 years. 10,000! Do you have a chance to be the one that your candidate chooses to pay attention to, or will you just end up as more static in the background of their day?

LinkedIn has seen meteoric growth over the past few years, emerging as a ubiquitous tool in recruiting. How can 300 million people be wrong?

But let's say you do find the perfect candidate, and they're not burnt out on being written 20 InMails a day, you still have to keep in mind that there’s a very high probability they’re already actively employed. Convincing them to switch teams can be a tall order. When you come across your purple squirrel, make sure to utilize common connections within your organization. If your candidate has a common friend or a business associate, this connection can turn into your best recruiter. It also doesn’t hurt to have a candid reference.

You should also take all of the candidate's information with a grain of salt. While it's against LinkedIn's terms to post fake information, there's really nobody policing it. With 300 million profiles, would anyone notice if I suddenly changed my current job to CEO of Apple? What about King of Gondor? Nah, that one doesn't seem believable. Scourge of Mordor sounds more inline with my prior job experience.

So, if you have the time, the level of access, and the wherewithal to do so, we encourage you to search on LinkedIn. Your perfect candidate is out there, but finding them is only half the battle. Trying to stand out amongst all the noise, and convincing them to join your team is an art in and of itself. For an extra edge, see our blog post: Writing the Perfect InMail on LinkedIn.

Below, we've included a few pros and cons to using LinkedIn as a sourcing method:

• All Encompassing: Everyone’s on it. You’re on it, I’m on it, your future talent is on it--whether they’re looking for a job or not . • Time Consuming: Learning to use LinkedIn is easy. Learning to use it like a professional recruiter is no small task. • Up to Date: As long as candidates are actively job searching, profiles are typically updated with their most recent experience. • Global Talent Pool: The sheer volume available can be overwhelming. • Photos: Having a face to put to a name helps hiring managers see applicants as people rather than just resumes • Passive Candidates: Many candidates are actively emloyed and not currently searching, leading to few positive responses. • Search: Solid search technology allows you to get very granular on the type of candidate you’re sourcing. • Pro-Candidate: Passive candidates can negotiate from a position of power. You need them more than they need you. • Reference Checks: Allows you to easily find common connections for candid reference checks • Quickly Escalating Cost: The free version won’t be very useful, but the corporate recruiter plan costs over $8,600/year as of this publication.