The progressive of every business is measure by the rate of turn over and profit, this the totally depends on level of patronage by the customers.
To get customers to get your product is kinda simpler task compare maintaining them, this is where exceptional skills of professional marketers comes in to play.
As a business owner or sales rep, it is very important for you to be very smart, tolerating, respectful, accommodating, out spoken in your communication and you must not be shy to your customers. Once you posses all the customers you will be able to good relationship with your customers, you could also Contact them on casual bases just to check on them. Most customers are carried away with the fact that customers are always right so as business or sale represent you should treat them like king and queen