That's actually a pretty decent trick. Theory 11 tends to hold it's magic to a higher standard than penguin does. I can understand that theory 11 didn't take the trick. Honestly I've seen some really bad tricks on penguin that aren't even really tricks because they're so obvious to any spectator. This trick is better than some on penguin.
There was a quick flash in your video of the gimmick, and the way you did your spring seemed a little awkward. probably from the gimmick. I don't think that the card can be handed to the spectator afterwords. These things would influence the decision of magic companies on weather or not to sell your trick.
creating magic is really cool and I encourage you to keep creating more magic. I would suggest that you perform the trick to many different people to really get a feel for how good the trick really is, before you try to sell it.
I've actually been trying to find different ways to do basicly the same trick. The ways I've made don't involve gimmicks and they're more advanced handlings than yours. But it's not bad.
This is just a tip for your performances. When your showing something trying to be "fair" and showing it's a normal object, if you only show one side while trying to work with your angles for the other side it makes the act of showing it very suspicious to a spectator. A casual showing of the object for a second, acting like you don't care if they see it, is more than enough. Like with gimmicked coin that you can only show one side, you are just going to casually show them "this is a coin" with it face up on your palm, not "is this coin normal?" showing only one side. That's a common mistake tons of magicians make. I made that mistake all the time when I first started.
I hope you keep performing, creating, and perfecting your magic.