There are two main reasons your content may not be showing on your Facebook followers' newsfeeds. First, Facebook sorts through content and decides what will show in each individual newsfeed with an algorithm -- Edgerank. Secondly, the personal settings of your followers may be prohibiting your messages from getting through to the newsfeed.
The Edgerank algorithm is based on three factors: affinity score, weight, and time decay. The affinity score looks at past behavior to determine whether or not a post will show; for example, if the user regularly interacts with a certain person or brand page, posts from that page are more likely to show on their newsfeed. The affinity score is a bit of a catch 22 because the more interaction your brand gets, the greater the likelihood of your content showing up on a newsfeed. The tricky part is getting that initial engagement (that's where an expert comes in handy).
Weight is another factor considered by Edgerank. It considers the type of content a user normally engages with, as well as how much engagement a particular post is receiving from other users. The third factor is time decay. Understandably, the newer the post, the more likely it is to be seen. This factor can be more easily manipulated by marketers. Simply, try to post while your followers are active on social media for example content posted at 7:00pm is a lot more likely to be seen than content posted at 2:00am.
The second major reason followers are not seeing your posts is their personal settings. Users can filter what type of posts will appear as well as which friend's posts will appear on their newsfeed. This is where categories such as acquaintances, co-workers, close friends, and more come in to play. These categories can be filtered out of the newsfeed.
A basic understanding of the Edgerank algorithm will enable you to cater your social strategy to better reach your followers; no use creating great content if no one is viewing it.
In the world of social media, slow and steady wins the race. High levels of engagement does not usually happen overnight. Slowly but surely, if you are posting content that is relevant to your followers, Edgerank will pick up on it and your engagement will continue to increase. Preventing your followers from blocking your brand page from there newsfeed is up to your content. Discerning the initial reason your followers liked you to begin with is a great way to determine which type of content is going to best serve their content wants and expectations.