How are you bringing more value to your customers than anyone else?
Our goal is to always be in the lead in our industry, in our markets. We do that in many ways, but one way that we can guarantee we stay top of mind and in each of their contracts is to consistently be bringing them value on a consistent basis. This doesn't allow others to move in when we unintentionally drift away because they are "locked in" or "they don't need what we offer", etc... They may not use the products, but everyone likes to know that they were thought of. Use the CRM that we have to see your client list and then leverage that to make sure that no one is slipping through the cracks.
If you're unsure about calling someone, that is probably the person you NEED to call the most. Overcome any fear you may have and go for it with a positive attitude and smile.