A candidate will want to interact with a recruiter for all the same reasons that people deal with realtors rather than buying houses from pictures on the Internet. Prospective house buyers want to deal with someone who can show them around, give them advice, tell them things they wouldn’t otherwise know about the neighborhood, etc. The system might not be perfect, but dealing with an agent or consultant when you are buying a house is something that’s the norm the world over.
A good recruiter provides a whole range of services completely free of charge to a candidate. These will include a cross section of opportunities with different types of companies. Often a candidate has a clear idea of exactly what they think they want, but when presented with an exact match it frequently doesn’t feel right. A good recruiter can present a variety of options — and candidates regularly end up going for the option that matches their initial ideal the least on paper.
A good recruiter will negotiate the best salary without pricing you out of the market. This is a lot harder to do by yourself or direct with the company.
A good recruiter will prepare candidates for interviews with information on the person they are meeting, their background, interview style, and typical questions. They will give the candidate ideas how they can sell themselves and provide coaching on difficult questions. They will fill the candidate in on the company values, goals, successes, and in generally provide an insight that they would not otherwise get.
A good recruiter will expedite the recruitment process so that if multiple offers are likely, they will come through at the same time — and they will also coach a candidate through their resignation to make the process as painless as possible.
All of the above applies equally to permanent and contract hires. However, with contract hires the recruiter will also normally take care of all the employment and payroll issues both for the hiring organization and the candidate making the experience of hiring a contingent labor force truly hassle free. With the growth of contingent labor, particularly in the U.S., this is a huge value add for companies and candidates.