Abstract: A method includes receiving, by a content server including one or more processors and from a client device, one or more characteristics of a particular content delivery opportunity, obtaining, by the content server, a watermarked digital component that is stenographed with a watermark representing (i) a payload that triggers an action by a client device that detects the watermark and (ii) a reporting location that is contacted by a client device in response to detecting the watermark, generating, by the content server, combined content by combining the watermarked digital component with content from a source that differs from a source of the digital component, and providing, by the content server and to the client device, the combined content.