Facebook has built-in analytics called Insights. If you are an Admin, from the top of your Page you can see the basic Insights chart showing purple dots for each of your posts, a green line for the number of people talking about your Page, and a blue line that shows the reach of the post.
Typically it's the reach that people look at to measure the effectiveness of their posts. "Reach" represents the number of times your Page has somehow appeared to other people on Facebook. In the simplest terms, those appearances could have been in the Ticker on the top right of your feed page and in the list of Stories shown on your feed page.
In a more abstract measurement, the number of people you actually reach is also measured by the people who Liked and Shared your post through friends of friends and fans; then the number of friends and fans that reshared and further liked your post.
Sometimes your post becomes so popular that people will share it over and over again, and each share will generate its own set of Likes. Unfortunately when this happens the origin of the post eventually gets lost. If your page has 80 fans you might be reaching 4,000 people. But even though your posts reached 4,000 people only the first 7 or so knew that the post came from your jewelry store because those are the people who actively engaged your post from your Timeline. The other 3993 people saw the post from friends, or friends of friends, and so on and so on...
Facebook keeps track of whose post you look at every day. Every time you engage a post (like, comment, share) you are creating a connection between yourself and the person who shared the post. As soon as that connection is established, you will immediately start to see more posts from that person.
As an example, Facebook will create a virtual connection between you and me if I click one of your shared photos. You might not know who I am and you will never see one of my posts, but since I clicked your photo, Facebook will start to show me more of your posts. Facebook will create an even stronger connection if I Like or Comment on one of your posts. Before I realize it, my News Feed is overwhelmed with all of your shares, likes, and posts.
I want to make sure you understand what happening, so here's a more specific example...
As a jewelry store you will post photos of rings to your store's Timeline. Then as the jewelry store owner you might share your store's photos through your personal profile. Since I'm your friend I will see your reshare photo. A connection is established between you and me when I like your shared photo; the connection will not be between myself and the original source of the photo--your store.
As an Admin of your Page, Facebook will show you Insights that 1 person shared your photo (you) and 1 person Liked the photo (me). If you have 100 friends, and I have 100 friends the "reach" will be 200 because your 100 friends had the chance to see your Share, and my 100 friends had the chance to see my Like.
As the jewelry store owner, the hope is that someone would look at that shared photo and follow back to your page, and then Like your page. Those 4,000 reached people don't really matter, only the few who trace back and Like your page will matter. Also keep in mind that you want people to like your page for the right reasons otherwise thousands of page fans won't matter either.
It's a slow process to reach enough people who casually trace a post all the way back to its origin and Like your page, but it does happen, and will happen faster if you post more often. You could speed up the process by posting things unrelated to your industry... some recent unrelated examples I've seen include questions like these:
"It's Fun Friday! The great debate... Coke or Pepsi?"
"What has been your favorite Olympic Moment so far?"
Sure, you might get engagements and people liking your page because of these two posts, but neither of these questions represent your brand or build relationships with jewelry buying customers. These are typical posts designed simply to increase Reach numbers to a crowd of people who are worthless to your bottom line.
And that bottom line is that you need to build the correct audience through sharing of your products and services. You can do that by posting photos or sharing website links. You should also reshare posts from other Facebook pages and websites that would be of interest to the customers you want to target.
When you post with specific intent to attract buyers it will take a little longer to build a Facebook following, but those that do follow will be more likely to click through to your website, buy something online, or eventually walk into your store.
I know this was another tough Nugget to follow. Let me know if this was too complicated to follow or it was appreciated.