Let customers know about the new great features that are being released. Yes it is easier to just release software but if no one knows about it then it does not matter what was released.
Tie your marketing efforts to your software releases and set goals for the customers you are trying to reach. This will raise the visibility of what you are doing and will bring value to your software product.
A simple approach can be a monthly news letters with links to youtube videos that showcase the features. After a short time you will have a library of help videos. It is not always wise to include everyone in your crm system with these monthly newsletter. Instead try to target specific market segments that make sense, measure, then try again.
This all goes back to my theory of running everything as an experiment. The key is to define first what you are going to measure, run the experiment, then actually measure.