There's a very simple formula, and that is to humanise your business. Put a face/person to it so to speak. Then, the people who 'like' the business page, will get decent, curated content that they like (otherwise, they wouldn't 'like' the page). Rinse, repeat several times a week and you do get a very good following and interaction.
Sadly, the article (in my experience) is right, organic is no longer a thing -- you really have to 'boost' a post for it to be seen by a good number of people (or just get really lucky). This was not the case about a year ago -- you'd get a decent amount of 'reach' and interactions with said post. It just simply doesn't happen now for the majority of pages as Facebook is trying to goad people into paying for each post.