Hiring a contract recruiter is a simple and manageable way to solve short term recruiting needs. Technically this is not a form of HR outsourcing but we'll talk about it here because the function is being done on a contract basis by a person who is not an employee but more of a hired gun.
At times a company needs lots of people quickly and a hiring manager or HR person doesn't have the time it takes to plow through hundreds of resumes, do phone screens, schedule interviews etc. If the company is not big enough to invest in someone full time, then a contract recruiter is a perfect solution.
Here are a few reasons to use a contractor;
It is entirely possible that hiring a contractor is not the best option. For example, what if the problem is not a time or knowledge problem but a resource problem? What if your company does not want to invest in advertising or job boards to locate candidates? What if you only have 1 or 2 positions to fill a year or they are highly specialized positions? Company does not want to invest in an applicant tracking system?
In these examples it is not a time or knowledge issue, it is a resource issue. If you hire a contractor and do not provide the resources to be successful, chances are like any other job he or she will likely fail.
Here are some tips on what to look for if you decide to in source.
As with outsourcing, hiring a bad contractor to do your recruiting can be a waste of money so make a good choice. It is also in your best interest to make sure the individual is not also doing recruiting on the side for him/herself while using your resources. The best bet is good old fashion references and a thorough background check.