cancelations_presenter.rb

module Quarterly
  class CancelationsReport
    class CancelationsPresenter < SimpleDelegator
      
      def subscription_totals(start)
        subscriptions.active.where("created_at < ?", start).count
      end

      def new_subscriptions(start, ending)
        subscriptions.active.where("created_at between ? and ?", 
                                   start, ending).count
      end

      def subscription_cancelations(start, ending)
        subscriptions.where("canceled_at between ? and ?", 
                                   start, ending).count
      end

      def net_subscriptions(start, ending)
        new_subscriptions(start, ending) - 
        subscription_cancelations(start, ending)
      end
    end
  end
end

We care about "Active Subscriptions" so our net would be poluted with the odd canceled_at subscriptions. Our net total over the lifetime of the sub would be subs_total + new?