Inferring membership in a group may include receiving one or more queries from a user, where the one or more queries have a feature that is independent of a subject matter of the one or more queries and that distinguishes the one or more queries from other queries received from the use. Inferring membership may include identifying the feature; and, in response to identifying the feature, making an inference that the user is a member of a group based on the subject matter of the one or more queries, where the group has one or more characteristics associated therewith. Inferring membership may further include attributing the one or more characteristics to the user based on the inference; and selecting the user for distribution of electronic content based on the one or more characteristics.