But does volume of sales = volume of eliminations?
There may be something to be said for the lack of a strong BE presence in rental fleets, and how this might speak to the present topic.
Lots of kids bought BE markers (obviously), but how many found them to be reliable enough to hang on to, and so kept playing with them?
In my experience BE was really good at getting kids in the door, but also really good at getting kids motivated to upgrade to something else, and in a hurry. So while BE produced loads of markers for really cheap, it didn't produce loads of markers that, once tried, made their owners want to continue playing with them.
Tippys are on rental fleets because they work. A marker that works is a marker that people want to play with. And a single marker that is played with eliminates a lot more people than all the markers in all the dusty attics and landfills, however many were made and sold.