Advertise site to get 100+ sales

The site (for freelancer staff : this are not my sites) [login to view URL] need 100+ sales of a seo-webservice. Customers could enter their website informationen (ste name, site url, site description) and upload an image. After payment this informationes will be populated at 100 different blogs. A list of the blogs could be seen here : [login to view URL] There is a german and an english form to enter the needed values. The user has to pay 5€ for this service. Your job is to adverstise this site so they get 100+ sales. The customer could refer to you at the upload-form. After 100 sales reached (after 60 days) you will get the project amount. If 200 sales reached (after 60 days) you will get the double project amount. And so on. If less than 100 sales reached after 60 days, you only will get a percentage rate. (e.g. 60 sales = 60%).