I bought a bunch of discs in Best Buy tonight and I noticed that 4 of the Naschy releases were there and they all had "BEST BUY & BEST BUY.COM EXCLUSIVE". Also EXORCISM and SORCERERS was in a thick double box while the other two were simply wrapped together in separate boxes. I don't know how they're exclusive to BB.com as I bought the werewolf and zombie titles on deepdiscount.com.
Speaking of CasaNegra, back when they first began, Best Buy was stocking their titles in the stores. I bought BRAINIAC, CURSE OF THE CRYING WOMAN and THE VAMPIRE COLLECTION which contained the classic THE VAMPIRE and THE VAMPIRE'S COFFIN. At least in this store they sold the titles. when others were released I asked about their availability and was told by a manager that they were beginning to downsize their lesser known titles to make more room for newer movies. This was sometime last year. But that all the films could be purchased online.
In all seriousness, whether the titles are in-store or only purchasable online, I can think of no one who would gamble on most if not all these older, obscure (to the mainstream) movies anyway. If you couldn't find them in the store, they could always be obtained online and more times than not, much cheaper than if you bought them in a store. The generation who remembers these are getting older or "dying out" and there are very few new fans for these. Possibly if some of these companies had another, more profitable source of income than those sustained finances could help maintain these slow sellers and possibly help get more desired films into the market.