Ambush Marketing is a marketing strategy in which an advertiser ‘#ambushes‘ an event to compete for exposure against competing advertisers. It is in fact prominent in sports and major events.
Certain brands pay for the sponsorship of the event and get publicity in return for that. However this concept of marketing takes place around the same event without paying the money. Brands other than the one which provided sponsorship lose out the opportunity of such publicity and hence find out a way to promote themselves in connection to the same event.