Definitions for "Ambush marketing"
Sponsorship tactic in which a company or companies which is/are not sponsors of a sponsored event attempt to capitalise on it via actions which suggest that they are sponsors of it.
the act of marketing a product or service in conjunction with an event or other brand without paying for the right... typically used when an official sponsorship opportunity is available but a company doesn't wish to pay the fee for the sponsorship or another company has already purchased the sponsorship.
a deliberate attempt by a company to associate itself with an event over and above the official sponsor. For example, one company sponsors a sporting event, but its competitor covers the area surrounding the stadium with promotional posters and merchandise stands.