Brian,
It is true that some people/companies may have trade secrets they would not want to share, but I also think you let the cat out of the bag with your comment about marketing. The "secret" is: you have to be innovative and hard working if you want to take your business to the next level.
Also, as you mentioned, many investors struggle. Before a person can take it to the next level, the first level needs to be soundly established. For an article on the basics of getting your business going, you can read "4 Key Strengths of Successful Businesses" on Entrepreneur.com.
You would probably agree that both beginning and successful investors and entrepreneurs should examine and re-examine their businesses regularly to make sure they are healthy and sustainable. Some good points to keep in mind are in an article on Inc.com, "10 Things I Learned by Studying Every 'Shark Tank' Pitch Ever Made."
You would probably also agree that to innovate, market, and be in business for oneself, there's one problem that isn't preventable, but it is treatable. For more, you can read "This is the Single Biggest Obstacle to Your Success."
It is no secret that if a person will make steady, continued effort at getting their arms and minds around these concepts and practices, they can be successful.
