One thing to note is that a lot of people these days have Pathfinder subscriptions. So there are a lot of sales happening that are just 'automatic'.
Since the release of the Gatekeepers AP, I've been mailed / PDF'd every thing Paizo makes for Pathfinder, including the PDF only Pathfinder Society stuff.
There's a massive value add in having a sub in that you get the books + PDFs for the cost of the (print books - 15%). I seem to get the Pathfinder Society stuff for $0, but that might be what everyone gets them for.
This can however, give local stores the impression that Paizo stuff isn't doing well - because for them it isn't.