It wouldn't be a 'pull' subscription, but people pay other bills regularly, a subscription doesn't need to be auto-recurring to be successful, that only prey's on people forgetting one month to get money out of the few that don't fully unsubscribe, it's a dirty practice.
so as a customer instead of 'set and forget' i have to set and set and set and set and set and set... sounds real convenient
i'd rather some 'trustworthy' (haha) entity like bitcoin.com (tradehill) built a set-and-forget system while offering full email notifications on every renewal or billing failure (or when top up is needed), and simple ways to cancel the subscription.