The MetaFace¹ system is being developed to provide a well-defined metaphor and metaphor-enabling framework for websites. This will be achieved through the use of a talking head, complete with facial animation, speech synthesis and artificial intelligence (an anthropomorphic metaphor). Of paramount importance to talking head technology, such as MetaFace, is the concept of believability. By creating a believable character, users are likely to spend more time using software because of motivational properties. Motivation can affect how long a user interacts with a website and thus is a very important aspect of e-commerce (and not just for online purchases). The Mpeg-4 standard is a key technology of MetaFace and similar systems because it includes specifications for facial animation and is highly efficient when communicating this data over the Internet. This paper discusses the technical aspects of MEPG-4 facial animation, how MPEG-4 can affect believability, and how to overcome any inhibitive aspects.