An analytics system and associated methods are disclosed. The analytics system may be used by site owners and others for various purposes, such as to identify and compare network sites that satisfy particular criteria, to identify and compare keywords associated with these sites, and to assess characteristics of typical users of these sites. One feature of the system includes computer processes for inferring characteristics of users for whom user profile data is unknown or incomplete, and for using these inferred characteristics to more accurately assess the characteristics of typical users of particular sites.