Remember when you were an impressionable kid, and you hung out with some new/older kids – maybe some fresh arrivals at school who’d moved from somewhere wild and exotic, like Peckham, or Shrewsbury? And they talked differently – they had different accents, and different names for snot or underpants?
Of course, to write effectively on a business’ behalf, you need to know your audience. You need at least an overview of what matters to them, the problems you can solve for them, what makes them happy, and so on. And you need to be able to distinguish your brand from all the others vying for the same audience’s attention.