"As a company grows, communication becomes its biggest challenge. If the employees fundamentally trust the CEO, then communication will be vastly more efficient than if they don’t. Telling things as they are is a critical part of building this trust. A CEO’s ability to build this trust over time is often the difference between companies that execute well and companies that are chaotic."

Awesome quote. From my experience, I would say communication is the greatest challenge for startups in general, whether they've just started or have established themselves and are growing. Without good communication, misunderstandings can easily become a huge headache and perhaps a show stopper.