In Canada it didn’t use to be caffeinated (non-dark pops weren’t allowed to contain caffeine, but things labeled as an energy drink were). That law changed a few years ago. Maybe that’s why it wasn’t as popular here back then?

That would make a lot of sense! If it was only popular because of the caffeine, and it didn’t have any, that would more than likely explain why I never really saw it in the 90s.