If you are hosting advertising on your Windows Media server, the
advertising content is treated just like any other content you want
to stream. You should use playlists to reference your advertising
content in order to better track the consumption of the advertising
content. Use
Advertising content that is used for site branding, such as station identifications and welcome messages, is often stored locally and referenced in wrapper playlists. Conversely, advertisements that play at various times during the user's session are usually included in standard playlists.