Sorry if this is not the right place to post this, but I keep running into this term but can't find info on what it is. So, what is print on demand?

"Print on Demand" as used by FFG means that for some smaller expansions and other items instead of doing a large print run at their normal manufacturer they will "Print on Demand" a small expansion at a state side or in house facility on an as needed/ordered basis.

In addition, because they are printed in-house, the cardstock and print quality is noticably different. This is important for (for example) draft or promo cards for LCGs as the card backs are noticably different. Because of this, tournaments require you to use opaque sleeves for any cards made with the PoD process.