Because Facebook uses a newsfeed to show users content from their contacts, that is where most of your followers will see your post. That means that it’s not enough to have your phone number and other relevant contact information on your Timeline – you have to include it in your posts, too.
The goal is to make it as easy as possible for customers to find you, whether they are seeing your content on a computer or on a mobile device. Facebook doesn’t have character limitations like Twitter, so that means that it’s easy to tack your phone number, web address, and other relevant information onto the end of any content you post. Customers are far more likely to patronize your business if you make it easy for them to find you.