An advergame is a game specifically created by an agency to promote a brand or a product. Advergames are most often online flash games and mobile apps.
The brand is largely exposed and the game may be related to the product or brand universe. For instance, a sport apparel brand can be promoted by a football advergame.
The branding impact and memorization are supposed to be higher for advergaming than for traditional advertising. Different factors contribute to this fact:
the brand exposure is longer
consumers are exposed on a voluntary basis
the player is engaged in the action
the play experience and relaxation favor memorization, brand attitude and proximity
Advergames are freely disseminated on the Internet. They have sharing functions.
An advergame is only one part of advergaming.
An example of advergame for Expendables 2 movie with a trailer, ticket buying options and sharing functions.