Student employment is favourable because of its exemption from contributions. Based on their full time status students have social security coverage so it is only the amount of personal income tax (15%) which is deducted from their gross wages. Recruiting — organizing tasks and all the administration are done by the student employment agency. You have to pay only after the actual working hours.
Distribution of flyers or working in a multinational shared service center? Any of them can be done by students.