If you have only one customer, are you really self employed? If you have 100 customers would you be more comfortable if one of those customers changed vendors than if you had just ten customers.
The biggest issue with large customers is they want you to change your business to suit them. Then you find that doesn’t work for the rest of your customers and now you have essentially created two(or more) businesses to suit your largest customer. Be very wary of doing too much custom work, as custom customers expect custom work at commodity pricing. Pictured above is a beautiful Dead Sea Mud soap loaf that we have requests for different custom looks and recipes all of the time. So far we have resisted and it continues to be a top seller for us.