Executive search firms need a good resume from you, but they also must have a search assignment that matches your background before they can be of service. Headhunters do not market you. They find the best candidates for client job openings. Their clients are companies that pay their fee or retainer. Don't expect a headhunter to make you her number one marketing project. Conducting your search campaign isn't her job, it's yours.

It is extremely unlikely that anyone coming out of school with a technical degree will go into one area and stay there. Today's students have to look forward to the excitement of probably having three or four careers.
Gordon Moore

To succeed in life in today's world, you must have the will and tenacity to finish the job.
Chin-Ning Chu