Ricardo, I've used a small dab of gorilla glue in the past with stickers or loose tape. I do know though that you'll get a fair share of collectors who say to leave it how it is. If you decide to glue, just be careful you don't get any on your fingers that will pull the sticker further from the bat. Maybe apply a small dab and hold down for 60 seconds with something like tweezers?

If you bought the bat from Keith on Ebay, that's nicer than the one I used to own in my opinion!