Gary Robinson is an American software engineer and mathematician and inventor notable for his mathematical algorithms to fight spam. In addition, he patented a method to use web browser cookies to track consumers across different web sites, allowing marketers to better match advertisements with consumers. The patent was bought by DoubleClick, and then DoubleClick was bought by Google. He is credited as being one of the first to use automated collaborative filtering technologies to turn word-of-mouth recommendations into useful data.