The fundraisers may be employed directly by the charity as part of an 'in-house' team. They may also be employed by an agency working specifically in the area of fundraising. In this case, the company is usually paid a fixed fee per person signed up. This fee depends on a number of variables, such as the number of donors required and the average annual donation desired. Though charities can normally expect to generate a minimum return on their investment of 3:1 over the duration of a donor's giving relationship with them.