The job hunt, driven by slothful job ads, results in a huge pile of not-necessarily related resumes. There is plenty of blame to go around. Any recruiter who doesn't work to polish the job ad to a precise solicitation is a fool. Any job ad distribution service that doesn't offer help is a waste of money. Any agency that doesn't insist that job ads are well written and compelling is cheating its customers.
Effectiveness is always a question of the right investment at the right point.
Understanding how to write the right job ad for a particular job board is the most expensive part of online recruiting. A more competitive one. Manage every step of the placement process. Establish a stronger presence on the web. Call, fax, write, email.