How is email the best? This is a business, email happens to be free, but that doesn't mean people will read it, etc. It could well be that it's more profitable

How is email the best? This is a business, email happens to be free, but that doesn't mean people will read it, etc. It could well be that it's more profitable to pay Facebook than to use email, similarly to how buying the most expensive location for your shop can be more profitable than the cheapest location. God forbid, you try to open a business on land that is 'free'. Fundamentally the people in the article are getting more than 50% of their business from Facebook, it's clearly a valuable service.