I hope it doesn't happen bc I think sometimes money can ruin things like this. When the goal becomes money, that begins to take away from what the real goal should be. Its kinda like how some musicians make their best work before they become famous. Once money enters the equation, creativity begins to suffer.
You made a good point but I'm thinking more on the lines like giving someone a tip. I work in a Deli and often will be offered a small tip for doing a good job. I don't think I'd MAKE people pay for a map, but it would be generous to get something here and there.