What does it mean to be popular? In my Twitter stream and across the media landscape, I see endless references to Mad Men and Girls, but those shows are watched by relatively small audiences. So are they popular? We’ve never been able to measure popularity as instantaneously as we can now. But popularity means something different today than it did before the Internet era. As Adam Sternbergh writes: “We, thanks to the increasingly concierge-style delivery system of the Internet, are each sheltered in our own cultural cocoon.” From movies and television to candy bars and digital downloads, here’s the NYT Magazine with a look at what was, is, and will be popular.