Pre-ordering is dumb because they are just collecting interest on your money. Granted it isn't a lot, but you factor in a bunch of pre-orders it is free money for them. Basically a loan, on which you get nothing.
In the context of a work of fiction, the term canon denotes the material accepted as "official", in a fictional universe's fan base. It is often contrasted with, or used as the basis for, works of fan fiction, which are not considered canonical. It is used in two slightly different meanings: first, "it refers to the overall set of storylines, premises, settings, and characters offered by the source media text". In this sense, canon is "the original work from which the fan fiction author borrows," or "the original media on which the fan fictions are based." Secondly, it is used "as a descriptor of specific incidents, relationships, or story arcs that take place within the overall canon"; thus certain incidents or relationships may be described as being canon or not.