Web targeted promotion

Hi, We're looking for an expert to pomote our service to college students. We are looking for college students to sign up on our site for free to provide freelance services as tutors, babysitters, and translators. Creative promotion welcome. No pay-per-click please. No paid advertising. This will be long term project. We need US college students currently. Willing to pay $30/month for one year. Pay monthly and would like to terminate the service if no result generated at the end of each month. After the 1st year, we could pay more if good results are received. Thank you.