In order to stay in business, it's important to have the fundamentals right. A very basic fundamental is managing the cash flow of the business.
Cash is literally the life blood of a business.
If a business isn't adequately capitalized, it won't survive. They grow by reinvesting the earnings of the business. Most businesses experience cycles of good times and bad times, growth and retraction. Further, without reinvesting earnings, the company usually will be unable to exploit the opportunities of the good times by financing expansion. Many of the founders of companies that are now prominent lived modestly, even after their companies became successful.