When internet marketing you would track what emails are profitable and keep them in the loop to resend it. If an email gets you 50 or 60% sales then you need to try to recreate the type of content and the set up you used. Also you would make sure to send those emails to new subscribers as well to keep the sales flowing.
When you are communicating with the customers on your site, try to be unique and interesting. If you come across as a robot with no personality, your customers will be drawn away. Developing a personality on your site, will help establish a stronger personal connection with your potential customers, yielding more sales.
Communicate with your fans as often as possible through your site and different media outlets, such as MySpace and Facebook. Ask them exactly what they would like for you to do better and the products that they enjoy. This feedback could be used to innovate your product and is a useful tool for customer satisfaction.