[adibitar69]

Before Google implemented quality scores for search advertising, Google searches were overrun with irrelevant ads that linked to sites with little content. Any marketer could bid on nearly any term and show in the paid results and placement was simple: higher CPC bids equalled higher ad rank. This created an overall poor search experience for the user. Google eventually improved ad quality by being the first search engine to assign quality scores, which attempt to measure ad relevance.