An exemplary method of providing content to users of a social networking service includes selecting a first set of users from a plurality of users on a social networking service in a geographic region to receive personalized content. The method further includes setting a first distribution rate for the personalized content during a first period of time based at least in part on a first user-traffic pattern. The method also includes providing the personalized content to client devices of the first set of users in accordance with the first distribution rate during the first period of time. The method further includes tracking posting of the personalized content to the social networking service by the first set of users, and reducing the first distribution rate if a ratio between a number of times the personalized content is posted and a number of times the personalized content is provided satisfies a threshold.