Most likely the person and the business are the same. It is possible (unlikely but work with me...) people might buy subscriptions to 'blugill's insights' but I am the brand you can buy the business from me but if I don't continue to write the content everyone will go elsewhere. As such the billion dollars is because that is my real (lifetime?) income from it. similear for my novel, you would probably worry if I let someone else finish it. (Though wheel of time proves it can work)

Now there are plenty of newsletters that are not about the auther and many of them do well-

> As such the billion dollars is because that is my real (lifetime?) income from it

Okay, but you need to apply some kind of time discounting for future earnings. And then you're still left with the thorny question of whether the company is worth anything without some kind of perpetual employment contract. Hence the very low multiplier of 2-3x for newsletters.