Be the difference
You buy a candle at a farmers market. You get home and love the product. You look them up on Instagram just to tell them how much you love it. And you get no response.
This business is missing major opportunities. How far would a quick response have went? A simple, “Hey man. I remember you. Glad you love it. Come see us next weekend we will be there again.”
At the least the customer will consider coming to see you again and most likely follow you on Instagram. At the most he is now in love with your company and promotes your product you everyone he knows. He posts images of your products on Facebook and tells everyone how great they are.
This is why if you are a small business you reply to every single comment if it is any way possible. A couple seconds or minutes of your day can be a real game changer.