They are very specific offers and there are usually more than one type going around at one time. The rates can be pretty different. The "PIN craze" really kicked into high gear last October. I know there were some not so happy people b/c some had PINs that had (for example) Poly Garden View at $209 for both value and regular season dates and others had $235 for value and around $250 for regular, still others had no PIN at all.
they will be for specific dates. Right now the PINs that are floating around are for travel through early July at the latest.