You know you can just tell them they are doing a great job and to have a great day without the creepy, flirting bit, right? You can be nice to people and express gratitude and make people smile without bribing them with cheap candy as though you're trying to slip into their DMs.
Especially when I'm having a rough day, I do not want some random showering me with pity treats when I'm just trying to make it to the end of my shift.