I'm new to caching, so take all of this as coming from a newbie. My 3 year old son and I have started this up recently and have three finds. All of them are in Woodstock, GA - so maybe the issue is local.
When we get to the cache, they are usually full of what I would call "Happy Meal" toys. We basically trade one Happy Meal toy for another, he plays with it for 5 minutes (how much fun is a Happy Meal toy anyway...LOL), then it ends up in the toy box. We can put it on a shelf and label it as a cache find - but it seems pretty silly to label a hot wheels car, a robot, and a plastic wrench.
What suprises me is that there is no typical souvenier that is a keeper. Like a button or a hat pin that you can keep as a collection. My son and I are going to start a few caches, and we would like to have some simple, small (1") buttons made that just has a design that relates to the cache, kind of a momento of the trip for who-ever finds it. I'll throw some toys in for the kiddies, but the button is intended for the Dads or other adult cachers. It's more about the find than the "treasure" type of mentaility for most of us I'm assuming.
The geo-coins seems a little expensive and silly to me. It's about where WE go, not where the coin goes (again, this just my perspective).
The idea is to put 30 buttons as described in the cache, as well as 30 self-labelled envelopes. So, the adults would take a button and an envelope, and mail a buck to back to us to pay for the button. It looks like the buttons cost about .50 cents, so as long as every other person follows through, we break even. Furthermore, even if I don't break even, well...I don't really care all that much.
Good idea? Bad idea? Already being done in most cache's and I'm just not finding the right ones?