I came across a interesting article in the Canadian Journal of Library and Information Practice and Research, vol. 3, no. 2 (2008) telling a success story from the MSVU library when adding avatars to their library site. The reason why they decided to introduce the avatars is this: "Two talking avatars -- Sarah and Suzie SitePal -- were recently added to the MSVU Library website. By adding the avatars to the site, the Library hopes to make the site more interactive and fun for new and returning students. The avatars are used to welcome students to the Library, to highlight Library resources and services, and to relay information about Library events". Here you could see the avatars in action.