Embodiments of a mobile device and server system are described. The mobile devices communicate with the server system and present targeted content, such as advertisements to the mobile device users. The content is targeted based on usage statistics stored on the server system which were previously collected from the mobile device. The server receives the usage statistics collected from the mobile device, makes inferences about preferences of users by tracking application and/or content usage behaviors of the users, generates recommendations for advertisements targeted toward the users of the mobile devices based on usage statistics; and transmits the recommendations to one or more of the mobile devices for presentation to the user(s).