Ambush (Guerilla) Marketing in Search Engine (Google)

Ambush (Guerilla) marketing as defined by brandchannel.com is a term for when one brand pays to become an official sponsor of an event and another competing brand attempts to cleverly connect itself with the event, without paying the sponsorship fee and, more frustratingly, without breaking any laws.

Wikipedia has many good examples of famous Ambush marketing.

We've seen ambush marketing happened in events and games. Now see ambush marketing in the context of search engine marketing:

See Toyota's sponsored ads on the bottom right when you do a search in Google for the brand keyword' Holden'.