I hate to poop all over your interests, but I just don't see a single practical purpose behind releasing new cassette tapes.
Just seems like a silly gimmick to me. I feel like any case for tapes can be made better for vinyl, digital, or CDs. I mean, if it's just for collecting purposes, why not just sell limited edition t-shirts, posters, and bobble heads?
Don't let my disdain for your hobby bum you out, though! I just don't get it.
I totally agree with this. As a mega CD collector (~3,500) I can relate to the thrill of collecting but I don't get the appeal to cassettes. Vinyls (while also useless IMO) are cool due to the huge artwork but cassettes were weeded out for a reason. They're also easily destructable. The only cassette I have Peaceful Pachabel: Canon In D Major.