"Currently, the predominant business model for commercial search engines is advertising. The goals of the advertising business model do not always correspond to

"Currently, the predominant business model for commercial search engines is advertising. The goals of the advertising business model do not always correspond to providing quality search to users. […]. For this type of reason and historical experience with other media, we expect that advertising funded search engines will be inherently biased towards the advertisers and away from the needs of the consumers." The Anatomy of a Large-Scale Hypertextual Web Search Engine, Sergey Brin and Lawrence Page