I went back today, and sure enough, they had a fresh supply of stickers. I was told that within 30 minutes of my visit on Friday, they were resupplied. Pretty speedy service, if you ask me!
Apparently, the actual statue of this little guy - Manneken Pis - is the most photographed statue in Europe
Granted, 10% off of your bill isn’t a huge amount, but hey, every little bit helps.