A bombshell has exploded in consumer buying behavior.  Moving away from one-time purchase and donations, consumers are increasingly moving toward the subscription or sustained-giving model. For marketers, this shift opens the door to a new set of revenue opportunities.  But it also means some fundamental changes in how we market.  The subscription model that was once the sole province of book publishers and CD/DVD clubs has now gone mainstream.  Marketers in all industry verticals are awakening ...