Systems and methods of identifying information resources for content item placement campaigns are provided. A data processing system can identify a request from a content provider computing device via a computer network to initiate a direct content item placement campaign. The request can indicate an information resource. A content item slot of the information resource can be identified and a rendering of the information resource can be provided for display by the content provider computing device. The rendering can include a preview interface indicating the content item slot. Actuation of the preview interface during display of the information resource at the content provider computing device can be detected, and a content item associated with the content provider computing device can be identified. The content item can be provided for display in the content item slot of the information resource, at the content provider computing device.