Methods and apparatuses are provided for generating, updating, and using an interest graph. A plurality of interests representing a plurality of subjects' affinities towards a plurality of topics may be obtained. A processing device may generate an interest graph based on the obtained interests. The generated interest graph may include: (i) at least two nodes, each of the at least two nodes representing an interest of the obtained interests, wherein the obtained interests are free of any personally identifiable information associated with the plurality of subjects and (ii) at least one link connecting a first node to a second node of the at least two nodes, the at least one link representing a relatedness of the interest represented by the first node to the interest represented by the second node.