The local B&N here has about two shelves worth of TrekLit. Not nearly as much as once they had, but apparently a bit more than some other B&Ns you all have mentioned.
Managers often get a bit of leeway in what gets ordered. A manager with a keen interest in media SF and tie-ins will no doubt order in more media SF and tie-ins. If a few copies of each are pre-ordered, they are more likely to add a few copies to the order so there will be some on the shelves. Some stores are smaller than others, and the ordering might be done by an offsite manager, or someone who does not actually work on the shop floor.
This is why I say that ST fans who only ever scan the shelves, but don't ever tell the staff what they came in to find, are doing themselves (and other fans) a disservice.