He or she is, in fact, representing the employer's interest when you are interviewed. Treat the recruiter with the same respect, integrity and professionalism that you would want to present to a prospective employer. Be honest, positive, knowledgeable and confident. Do be honest. You will want to treat the recruiter much like you would a confidante because the more the recruiter knows about you, the easier it will be for her to find the right position for you.
Recruiters make great advisors and mentors.
With their knowledge of the industry, their fingers to the pulses of industry changes and their contacts, you may also learn much to assist you in your career decisions and career planning. The recruiter makes his or her salary by successfully filling a position. Usually this means that some or all of the expenses incurred are the recruiter's responsibility. Time is important to recruiters. So is their relationships with employers.