Manage your comments, if you have the "reply" option turned on—use it. Correspond with your customers directly to their posts. I often see large corporations with comment spam to another product that can even be a competitor product. These comments should be deleted when they occur and the creator banned for poor taste. It's your business page!
If your customers are leaving you questions in the comments, answer them. If it's your policy to redirect questions and concerns to an email address, let them know and be consist so the next person can follow the same procedures with continued requests to forward all questions to email@example.com. But, answering the questions in the threads will give many people the same answer eliminating your need to respond to countless emails.
Don't be afraid to use graphics, videos, and articles for people to engage more with your posts. The new algorithms used by Facebook has turned comments, likes, and shares into gold!
Learn more about me at https://www.facebook.com/VickiBezio or https://www.facebook.com/vixxbuzz..