This is a genius idea: QR codes made of chocolate. No, I'm not joking. Chocolate is serious business. From Chocolate Graphics:
Looking for a great new way to promote your company and products? QR codes allow anyone with a smartphone and a QR code reader app to scan the QR code and access websites, videos, coupons and more!
... Chocolate Graphics chocolate QR codes are not only delightfully delicious but are also a great talking point and marketing tool. Each chocolate features an embossed chocolate QR code design using a process far more advanced than simply printing on the chocolate.
Chocolate Graphics uses a unique patent protected process to create a finished product that is 100% chocolate (no inks or icing are used) and this unique feature results in a superior product.
Imagine being able to hand out a chocolate that will take readers immediately to a free first chapter, or an audio sample, or your book trailer (though I admit I'm one of those people who think book trailers suck; they are not worth the money), which they will then settle down to read/listen to/watch while eating chocolate. That, dear reader, is a triumph of associational good will for the book in question. The happy muncher will be hitting the Buy button before they know what they're doing.
I've written before about how and why to use QR codes (here and here). But I never dreamt up chocolate. It's pricey, but I'm thinking some of this might be in my future (and therefore possibly yours). Immersive reads like Hild pretty much demand chocolate.