Promoting the digitisation service can be possible via internal communications and media. An article published in the University and Library newsletters is a good way of building awareness of a service.
Outline clearly the benefits of using digitised materials, for both academics and users.
Create a web page for your digitisation projects and services and consider running seminars for library staff and academics. Look to Web2.0 technologies such as Twitter and blogs to get news out to your followers quickly.
Work with your subject librarians to raise awareness understanding of your services and projects.