My take(s) on the "D&D Popularity: Now vs the 80s" issue:
1) Anecdotal story: There was a brief time, when I was in 5th-6th grade (1985-86) when D&D was a huge fad in my school -- tons of kids had dice, and rulebooks, and created characters, and played the game during lunch & recess. In my grade alone there were probably 30-40 people who at least expressed some interest in the game and created a character during this period, which lasted for a few months. By a year or two later (1987-88) the fad had died, almost everybody had lost interest, and there were only about a half-dozen of us still playing D&D. However, in the fad days the vast majority of those 30-40 people didn't own any rulebooks (or at least a full set -- any given kid might own a copy of Oriental Adventures or Fiend Folio and nothing else, some might not own any rulebooks at all but might have a random module or Dragon magazine issue, and the majority had no D&D products at all) and didn't have any real idea of the rules or how the game really worked, they were just interested in something new (and vaguely illicit) that the other kids were into. Whereas, later on when there were only 6 of us, we all owned full sets of the rulebooks, modules (even those who never DM'd owned at least a couple modules), and a couple of us were subscribers to Dragon, RPGA members, and even went to the local sf/gaming con. It's a fair estimation that TSR saw as many or more sales from just the 5-6 of us in 1987-88 as from the 30-40 people in 1985-86. This is, of course, purely anecdotal and statistically meaningless, but I suspect it holds fairly true for the larger population -- in the 80s a lot more people were "involved" with D&D but weren't necessarily turning that involvement into product purchases; nowadays there are fewer total people but they're more fully invested in the hobby and buy a lot more products per player (and are more likely to go to cons -- even of our 6 dedicated D&D players in my school only 3 of us ever went to a gaming con, and only I ever went to GenCon).
2) Another point: in the fad days of the 80s, D&D was popular almost exclusively among kids (up to college age) -- there was a cadre of adult fans (mostly the early adopters from the 70s -- D&D's original target audience) but they were a tiny fraction of the total fanbase who were buying D&D sets at toy-stores (I'm guessing way less than 10%, probably more like 1%). Nowadays, D&D has a very significant adult fan-base (every demographic survey here shows that most of us are in our 30s and started playing in the period 1979-86) that's by and large completely separate from the current youth fan-base (which I have no idea how big or dedicated it is) so it could very easily be the case that while neither the adult nor the youth fan-bases of D&D are individually as big as the youth fan-base was in the 80s, the combined fan-base could be bigger.
These two factors, especially in combination, could easily explain why D&D sales are as strong, or stronger, than ever, but the game "seems" less popular than in its fad days.
I was not lip sinking!
