The problem with attractional evangelism and ministry is that it requires you to out-do yourself week after week. Those who showed up for the giveaway, might stay because they've found God or discovered that Christ has always been present in their lives but if they came for the novelty of the car, and you don't have another novelty lined up, the emptiness of attractional evangelism will fall flat and the 51% increase experience will dwindle back to the norm until the next over the top outreach attempt.