Google obtain a patent that allows Google to track your pointer moves for search results. The patent "System and method for modulating search relevancy using pointer activity monitoring" was filed in 2005 - -means that your cursor movements may indicate to Google how to rank your query results and consequently, this'll affect marketers' campaigns in their ad placements.
Google in its filing explains that; "A typical user's behavior is to move the mouse pointer (or any other pointing indicator) over or near a target informational item, keep the mouse pointer there for a period of time while the user reads the item's information (e.g., title and snippet), and then click through the underlying link or move to another item. Sometimes, a user may review multiple informational items responsive to a search query, moving a pointer over or near each of the informational items that the user reviews. These various pointer activities can provide another way to evaluate the user's feedback with respect to a particular informational item."
More Info: Google Patent