perhaps: 1) a set of timers- days, weeks, months, as appropriate for your subscription units. 2) a data model with users and subscriptions and a means of cros

perhaps: 1) a set of timers- days, weeks, months, as appropriate for your subscription units. 2) a data model with users and subscriptions and a means of cross-referencing them. subscriptions are time-stamped upon creation... 3) a set of routines that perhaps runs daily that compares now (Date().getTime()) with subscription timestamps then compare to timer-values and mark subscriptions as desired "expired" or maybe "one week before expiring" and thus worthy of an email etc... 4) a means of notifying the client of a users subscription status. (additional field on published user object etc?) 5) a means of restricting assets, probably in the router, based upon #4...