The Illusion Of Danger
If it's got wheels, a kid will try to ride on it. Might as well just skip the middleman and throw on a saddle.
Your child wants to do one thing the most. What is that thing? ANYTHING TRANSGRESSIVE. Face it, if your child has a chance to feel like they're breaking a rule, they're gonna race for it. And where's the place with the most rules in the world? You got it. The airport.
So here's the choice: either your kid gets to sit in a TSA clean room while the FBI asks you what country a Charmander is from, or you channel that restless naughtyness into a suitcase they can ride! Imagine the thrill of being towed on top of all the clothes and shoes that are tucked into lightweight durable plastic! The joy of swinging a matching tote and kicking one's heels against the matching saddlebag! The glory of being the only one who's actually ON the suitcase rather than dragging it?
And, if that's not enough, the cute little Trunkis comes with a bunch of stickers that lets you put a face on your luggage. Over twenty facial features and fashion accessories let your child BRING LUGGAGE TO LIFE. Imagine the scowls from the angry old lady across the way! But she won't be able to do anything, because riding a Trunkis is TOTALLY 100% LEGAL!
It only FEELS transgressive. Which is perfect for a little kid.