I have had some scary-*** paintball friends. Most of them were snipers, but always at ranges under 90 feet. We played in a long, narrow gully with tall brush down each side and a road through the center. The field was silent until the first shot was fired, then there would be about ten seconds of intense fire, then silence again. I tended to snipe at about 30 feet, from behind my target. The essence of a sniper's art is silence in movement, not allowing his position to be detected, and stopping the enemy where necessary. Stopping the enemy everywhere as a sniper gets you shot. Stopping the enemy on your own ground wins the game. One guy had a little pocket that he controlled exclusively. He ranged in every spot that was viable from his hide, then waited patiently like a trapdoor spider (He was colorblind, too, which helped).
Remember the snipers at Stalingrad. True, they were operating weapons with an effective range of about 400-550 meters, to kill. But their techniques are applicable. One guy had a personal trench network, with little white flags and helmets on sticks that he could agitate at a distance. When he saw a kraut helmet stick up out of the rubble and heard the German call for surrender. That was when he fired.
And I agree that a sniper's first job is surveillance and reporting enemy movement. Intelligence is key, and don't anybody dare try to say it isn't. With a radio and a decent position, a sniper could warn of enemy movement and thwart it long before it materializes into something meaningful.