Hi Ali,
Recruitment cost would be the sum total of all the expenses incurred while hiring, e.g., Consultant's Fees, Print Ad Charges, Payment under Referral Scheme, Travel Related Reimbursements, etc. Tracking recruitment costs through various sources of recruitment and comparing them with results/responses helps tremendously in chalking out a Recruitment Mix Strategy. At the end of the day, everyone looks for the speediest recruitment at the lowest expenses.
Hope this helps.
Tx,
Rajesh