Free: Contests & Raffles.
Just because a spot isn't a secret, doesn't mean it can take an unlimited amount of hunting pressure. I'm surprised at how many guys will throw their own hunting or fishing spots to the wolves online. I've seen fishing holes beat to hell under the excuse that "it's not a secret." Before you know it, a place that comfortably fishes 4 or 5 guys ends up with 20 rods on it.
But every year I find more and more people were I hunt and fish were there has just been me and a couple others