Not only this, but blogging can also be a marketing tool, where you (or a company you're writing for) publish articles not as an end in themselves, but as a way

Not only this, but blogging can also be a marketing tool, where you (or a company you're writing for) publish articles not as an end in themselves, but as a way to show you're an expert in a given domain. For SEO reasons, but not only. These blogs don't need advertisement to make money, they are the advertisement. I'm pretty sure nowadays, this is where money is in blogging. If you want to make money as a blogger, I think it's a way safer road than the advertisement-centered approach.