Conventional Web interfaces respond to and consider only mouse clicks when defining a user model. We have extended this and take into account all mouse movements on a page as an additional layer of information for inferring user interest. We have developed a straightforward way to record all mouse movements on a page, and conducted a user study to analyze and investigate mouse behavior trends. We have found certain mouse behaviors, common across many users, which are useful for content providers in increasing the effectiveness of their interface design.