Dear Prathima,
head hunting is now one of the most used technique of recruitment. however the same is used mostly for top notch positions like CFOs, CEOs, FMs, GMs, HR Mgrs etc etc.. the same is due to the reason that people for such position rarely circulate their cvs and also the company who wants the position to be filled may require candidates who is presently either working for the competitor or another company in the same line. also head hunting is used bcoz it gives a guarantee for the credibility for the candidate. head hunting is becoming highly popular and is used more than it was in the past. another reason for the same is that it saves time - time for screening and shorlisting etc etc... also the qualifications for such position may be kind of rare to find. well as for future of head hunting its bright

.. there are recruitment firms who have specialized themslfs in head hunting and blv me.. its BIG money!!
hope the above gives you some info...
Cheers!!