Simple changes to a know practice can result in rewarding results. Walking the streets of Italy, I saw parked cars with leaflets placed under their rear window wiper. The fact that most of the rear windows were more vertical than a front windshield made them visible to pedestrians. The audience for the advertisement suddenly included those walking past. The potential audience was significantly higher for advertisement placed in the rear window compared with those left on the front windshield.
Have you considered how a subtle shift in current strategy might increase your audience dramatically? How do you measure new opportunities?