Have you ever purchased a piece of nice wood like a piece of trim, or a wooden cupboard door knob, or some unfinished furniture and have the price sticker sitting right on the finished face? Just peel it off and you can see all the glue that stays on the wood. Then you use solvents, and often the glue just goes deeper into the wood. You sand, and it tends to go down and in as much as off. Scraping shavings is about the only way to actually get it off.
If you don't work really hard you will end up with a stain blotch. So what do I do when I see stickers like that in a store? I take it to the manager, leave it in his hands and let him know that I am going to shop someplace elsewhere. How else will we manage to communicate to the store staff that this is totally unacceptable? Stickers can always be put on the backside of these wooden objects, where the stain doesn't matter -- not on the face.