Email Marketing is one of the most effective methods of engaging with your customers and prospects. When conducting email marketing campaigns, the email marketing metrics associated with that campaign will indicate how effective you were in achieving your goal.
However, if you make your offer compelling enough, they will be responsive and continue to engage with your business.
If you have been relying on this method to market your services and you are not receiving too much of a positive response rate, then you are not using email effectively.
The only way to identify that your efforts are not overly effective is to analyze the metrics associated with your emails. Your email marketing metrics will indicate how well you are doing, and how responsive your subscribers really are to what you are offering.