Most businesses don't begin with a strategy. 

They start with a product, an idea or a deal. 

Then they fight their way to some kind of product-market fit in order to survive. 

 As they do this, they use product or problem stories to create demand.  (You want to kit out a bedroom for £500? Want to transfer money overseas without being gouged? Is your child struggling at school? Well.......) 

If they make it to a certain size they encounter all sorts of other people - investors, distributors, new hires -  who insist that they explain themselves.*  

This is when they develop a strategy story - an argument about the future and the firm's place in it.   Essentially this is a narrative about your product-market fit that stands up to professional scrutiny. 

One of the challenges for a leader is that as the company grows, she moves from being in a market about furniture/money transfer/education apps and starts performing in a market that's about credibility and meaning.  The strategy story is there as a reliable tool to impress and convince people and occasionally just keep them at bay. 

* If they are venture-funded their strategy story will be vital from the start. This means repeatedly answering the questions "What’s the gap?" "Why you?" by people in rimless glasses and black sweaters.