Ambush marketing is a marketing strategy where a business organization tries to reap the benefits of an event without being its official sponsor. It has become an important part of the modern day marketing world. However, ambush marketing is a very controversial topic because many question the ethics involved in it. Besides this, another negative aspect of ambush marketing is that it ultimately reduces the value of sponsorships as the sponsors realize that any benefit that they receive by sponsoring the event will be reduced to a great extent because of ambush marketing. Sponsors, therefore, take recourse to various legal measures to stop ambush marketing from taking place. But it can still be successful, provided it follows some basic principles.

The term `ambush marketing' was coined by Jerry Welsh. Ambush marketing connotes a type of marketing strategy where a business organization tries to identify itself with a particular event which it has not sponsored but which has been sponsored by its rival. Ambush Marketing has also been defined as follows: Ambush Marketing occurs when corporations that do not have official sponsor status, gain access to sponsor benefits or otherwise seize them away from the official sponsor. Once an event is officially sponsored by one organization its competitors cannot claim that they too are related in some official capacity to the event. Hence, they resort to ambush marketing. They endeavor to show that they are dedicated to the success of the event and try to cover up the fact that they are not officially related to the event.

Ambush marketing generally occurs at two levels-onsite and on media. Onsite ambush marketing occurs at the event itself and the area surrounding it, including the approach roads and so on, and covers everything from refreshments, clothing, billboards, posters, stalls and so on. Media ambush marketing, on the other hand, refers to the advertisements in television, and to an extent, in the radio and press. The simplest way to communicate any message to the public at large is to advertise through a well-known personality associated with the event. The public associates the personality with the event. So, when such a personality is shown in an advertisement endorsing a particular brand or a product, it creates an idea in the minds of the public that the product or the brand is also associated with the event.