I learned a long time ago there are three mainparts of operating a successful business — good financial management, good marketing/sales management and good human-resource management. All three areas must be strong and evenly balanced or you will have a business that is out of balance.
As I travel the country doing consulting I find most businesses are pretty good at the marketing/sales part, but are weaker in the areas of financial and human-resource management. This can cause hardship and even disaster for a business.