What are the best-kept secrets about business?

What are some things that people could benefit from knowing that is largely secret - in the sense that very few people know about it?

Rob Rawson, Founder Staff.com

1. It's easier to make money selling a product for $10,000 than 1000 products at $10 each. In other words, selling high value products or services will make it  easier to make money.
2. Your logo is unlikely to make any difference to your business - don't spend too much time worrying about it, and don't spend much money designing it
3. Many businesses bend or break the rules to be successful
4. Possibly the most important skill in business is not spending money (being very frugal)
5. Try not to hire anyone as a full time employee until you absolutely must. The alternatives are to hire people part time as contractors, or to get people involved and pay them on a results basis, but avoid anything that is going to create a fixed monthly cost in your business
6. You don't need an office to succeed in business and again, reduce any fixed monthly overhead that you can including not setting up an office until you absolutely need one