Storytelling, Authority, and Co-Creation: A Toddler's Perspective

My son is two and a half and has strong views on stories.
Sometimes he likes stories from a book - right now he’s keen on Maurice Sendak’s In the Night Kitchen, but before that he insisted most nights on a Kipper story by Mick Inkpen.
I like Sendak but I can’t be doing with Kipper - it’s whimsical hippie rubbish and what’s more it’s achingly slow. So every now and then I change something round to amuse myself. When Kipper makes a cake, instead of currants and butter I tell the boy he puts in sausages and ice cream.
“NO DADDY. NO sausages. NO ice cream.” He’s genuinely cross.
This kind of story is inviolate - changing the details ruins it. He won’t interrupt - though if you ask him questions about what’s happening, he’ll reply, or point things out in the pictures.
The other type of story he asks for are ones I make up. These have a list of ingredients which tend not to vary much - him, his brother, our pet rabbit, Muck from Bob The Builder, Spooky Spoon from Numberjacks. But he’s keen for the details of the story to vary, and often if I include something he’s not interested in he’ll stop me and change things round.
So this kind of story is malleable - he likes collaborating, remixing, providing inspiration. He’s comfortable with the idea of characters from different stories crossing over - as they do when he plays with his toys.
Text is ritual: story is play.

(I’m sure there’s lots of literary theory exploring this stuff, which I’m just dabbling with empirically as part of the whole parenting thing!)
But what does it mean for commercial co-creation, and brands or marketers wanting to make content people love?
I’ve been reading Henry Jenkins’ essays on spreadable content - as opposed to viral content. Spreadable media is changed and repurposed as it’s passed around: viral media uses the participant as a host to make perfect copies of itself. In a networked system spreadable media is more powerful; it becomes more relevant to more people because those people make it relevant to themselves.
When my kid wants a book he’s getting static content: he loves it, absorbs it, and drops it. When my kid wants me to make up a story with a mix of characters he’s getting spreadable content - stuff that exists in a continuum with his play. Children’s books and TV shows are a special case, of course: static content that’s specifically designed to introduce spreadable material into a child’s life and play. The kind of activities that are seen as weird, nerdy or piratical in adults are encouraged in kids!
Anyway, the lesson I’d draw is that if you want to make spreadable content you really need to be thinking in terms of toolkits as well as (not instead of) text. Finishing something might push it into the realm of the static and the ritual - so completion might be your enemy. But on the other hand you need some finished things as proof that your toys are worth playing with. After all, not just anything get into the set of characters my son draws on for his made-up stories - only the ones that really matter to him.
One last thing: making up the stories for my kid is a lot more challenging and enjoyable than reading them out. Spreadable, malleable content isn’t just good - it does you good.