“I suspect two factors go into that,” Hicks explained. “First being, Fate Core was much better known by the time it got its ‘dynamite moment,’ whereas Monster of the Week was considerably more obscure, so there was a larger potential untapped audience for the latter. Second, and more significant in my opinion, is that the Fate Core episode of Tabletop was a single episode of Tabletop, while Monster of the Week has been featured in the ongoing multi-episode "Amnesty" campaign that The Adventure Zone is running: they are up to episode #21 of Amnesty as of the end of January 2018. In this regard, exposure on The Adventure Zone for Monster of the Week is probably more analogous to Critical Role for Dungeons & Dragons.
The Tabletop Bump had been extensively analyzed back in the day, with Alliance Game Distributors sharing a study that showed a 79% sales bump a year after the episode was posted (see "The Tabletop Bump"). The scale of The Adventure Zone bump on Monster of the Week, depending on how you look at it, is probably close to 10X a year later.
The influence of The Adventure Zone podcast on sales is no surprise on the comics side of the store; The Adventure Zone: Here There Be Gerblins graphic novel debuted at the top of the NPD BookScan graphic novel charts and has continued to chart in the months since (see “July 2018 NPD BookScan – Top 20 Adult Graphic Novels”). While not selling as well in comics stores, it racked up over 4000 copies in sales through Diamond in 2018 (see “Top 1000 Graphic Novels – 2018”).
Click Gallery below for full-size graphs!