Your story spreads when your audience is able and eager to tell your story.
So.
Are they able to tell it? Do they get it? Is it crystal clear? Can they repeat it? In their language?
But also: Are they eager? Why would they want to tell it? Does it boost their status?
You need both. Easy doesn’t help if there’s no reason for your audience to tell your story. On the other hand, a strong reason to spread your story won’t help if it’s hidden underneath a layer of confusion.
The easier it is for your audience to tell your story and the more the telling of your story boosts their status, the more likely it is that your story actually spreads.