American Express's Open Forum list of the "10 Fatal Mistakes Most Small Business Owners Make" is spot on. This especially applies to small businesses. I see this over and over, basic things such as, "Who is the target audience?" are too lossly defined, or "Tracking and measuring activities." are seen as a wast of time, or "What is the [life time] value of a customer?" is answered with a blank stare or as the next [one-time] sale.
So much opportunity, energy and resources are wasted if these basics are not taken to heart.