What the Hell is...Piggybacking?

Piggybacking is where smaller brands use well-known brand names, trademarked terms, or slogans in their online search advertisements to draw traffic to their websites. It is a growing issue for search engine marketers and Fortune 500 companies as advertising dollars shift online where brand abuse is rampant. Google's trademark policy is hands-off and encourages advertisers to resolve trademark disputes directly with a company that they believe is violating their trademark rights.

Marriott International and American Airlines contend that this practice is potentially driving up costs and confusing potential customers. American Airlines filed suit against Google last year, arguing that unchecked piggybacking was a case of trademark infringement.

Origin
Piggybacking was initially a business term that referred to reducing costs by adding a new project to an existing one. It was extended to the online arena with wireless networks to refer to computer users hopping on an unprotected wireless connection.