If you already have customers who adore you, you must learn to take care of them, remember that new brands are willing to offer them the same as you but at a lower cost, we are not saying that you lower your prices, but that you establish a good relationship with your customers.
Try to share valuable information through a blog or send them emails where you inform them of the news that your company has for them, new products or services that may interest them. Try to follow their needs, if you feel that you can not do everything, seek the advice of a digital marketing agency.