The old product advertising of "back by popular demand" always was a gimmick. It was simply marketers' desire to extract the last drops of water from the well.
When SiriusXM says a certain artist's pop-up channel is "back by popular demand" for another brief run, it means said artist's management or label has made out another large check to SiriusXM. Billy Joel's channel is "back by popular demand" for the seventh or eighth time right now. I know the old has-been is still a musical god out on Long Island where so many of the execs live, but the idea that every time the channel is removed, a nation of subscribers starts begging for its return is not believable.