"What % have gone to children to be played with? Where is the farthest from the US that these marbles have been shipped?"
Speaking for myself only, I pass Jabos out to kids (and adults) I see in my psychology practice, and many of the kids my wife sees knock on my door after their sessions to ask me for a marble. I've seen them roll them down the stairs as they leave the building.
Also, my office is in a medium sized building, & I put marbles on the tables in the lobby as a kind of "catch and release" program. Some days I have to replenish them several times.
I've sent small bags of them (20 or so) to friends in Korea and Japan. And I bagged up most of a case of them as party favors for my daughter's wedding a year ago. My wife still complains about the boxes in the garage (& family room, & living room, & bedroom).