Just for curiosity's sake, how many flavors did he offer? Usually, I see a tobacco, light tobacco, and menthol at the kiosks. If you'd like to be enterprising, work on DIY and create some killer flavors. Take them to the kiosk and let him sell them on consignment... he gives you shelf space, and you give him a cut of each sale. Or, work a kick-back deal, where he passes out your cards and you give him a few bucks on every unit you sell. The clerk probably doesn't get commission on unit sales - hell, he's just happy to be vaping indoors and getting paid to vape. He'd probably love a few hundred extra in his pocket each week.
Run him some samples to demo for the customers, hand him a stack of cards, and $1 for every 15ml he sells for you. The customer is happy, in that they get more quantity at a lower price. And since your cost for making the juice is pennies, you'd be raking in the dough.
Go get 'em, entrepreneurs!