When someone “shares” a post from your Facebook business page, including a Facebook boost or advertisement, it’s a VERY GOOD THING.
A shared post means someone is trying to tell someone else, one of their friends, about your post.
A shared post means someone found it interesting enough to share with their friends on Facebook.
Here is an example of a Facebook boosted post that someone shared, in effect telling their friends about this charter fishing company.
This post was shared several times by different people.
There are three types of Facebook engagements, each progressively more valuable as far as the Facebook visibility algorithm goes.
The more engagement you get the more VISIBILITY and REACH you will get for an individual post.
Also, more overall enagagement is also going to increase the visibility and reach of your Facebook business page.
You can find these analytics in your Facebook business page INSIGHTS.