Disclosed are systems and methods for determining similarities in content preferences among a plurality of users and generating content recommendations based on a requesting user's content consumption history. A requesting user may access the recommendation system to request content items for consumption. The recommendation system may be configured to identify users having consumed the same or similar content items as the requesting user, and to determine a ratio of content items consumed by the requesting user and an identified user to the total number of content items previously consumed by the requesting user. In one embodiment, the system may determine a degree of similarity in content preferences between the two users based on an inverse proportion of a level of popularity associated with the content items consumed by the requesting user and the identified user (e.g., sampled user).