hi bala,
i think both the methods have some advantages and disadvantages. the disadvantage of one can be advantage of other.
the advantage of job posting is:
:- u can get updated CVs of only interested candidates. u can assume tht the candidate has read the profile and he is interested in all the things like designation, job profile, location, CTC etc. so it can be considered that he is currently looking 4 change and u can go forward.
in case of fresume search, u can not consider this all.
i think i have answered ur query.. if have any doubts, u can revert back.