The web is a multimedia environment that is very well suited to 3D, for instance. Promotional campaigns or new product launches are increasingly making use of on-line competitions to attract traffic, and arouse the interest of potential and existing clients.
Games can be promoted using all media: press, radio, packaging, ... In return for giving his name and address, the player can register and win a prize, for instance, or make use of a game. Viral marketing is very often used to promote the game itself..
The advantage is that you can build up an interesting
database of potential and/or actual clients