32. The machine system of claim 31 wherein the presented content includes audio content having silently embedded codes therein or concurrent codes transmitted in a transmission associated with the audio content.
31. The machine system of claim 26 and further comprising: an automated user activities monitor configured to automatically detect and record machine usage activities of the first user as applied to the machine system, including recent attention focusing activities of the first user that implicitly identify one or more of invisibly or silently embedded codes of, or concurrently supplied codes associated with, correspondingly presented one or more portions of content that are detected by the automated user activities monitor as being sub-portions of content predominantly focused upon by the first user in rule-defined stretches of time, the rule-defined stretches of time being specific to the first user and being indicative that the focused upon content is likely to be interrelated to a relatively current topic of focus or of interest of the first user.