A server system comprising one or more processors and memory initiates delivery of a respective message campaign that includes one or more messages addressed to a plurality of users. The server system receives, from the plurality of users, campaign-feedback data indicative of user interaction. The campaign-feedback data includes information that enables generation of campaign reports including quantitative information about the message campaigns. After receiving the campaign-feedback data, the server system transmits, to one or more remote storage systems, campaign-tracking data that is based on the campaign-feedback data and then receives, from a requestor, a first request for analysis of the campaign-feedback information. In response to receiving the first request for analysis of the campaign-feedback information, the server system obtains a campaign report generated using the campaign-tracking data from the one or more remote storage systems; and provides the campaign report to the requestor.