Create a great product then sell it

One mentality is that with the right sales pitch and landing page you can sell ice to an eskimo. The problem is that you are selling to make a sale instead of selling to deliver a useful product to your clients. This can breed resentment or even worse allow a competitor to come along with something the client actually needs.
This video of Steve Jobs pontificating about the demise of Monopolistic companies like Xerox and IBM strikes a chord with small businesses as well. While the video discusses issues at very very large companies the thinking is applicable to all size businesses.

Sure Sales and Marketing are important and investing in good training, well designed branding, and a healthy internet presence will help you sell more product. The pitfall that Steve points out in this short video is that at the end of the day what people are buying is the product. If you focus on Sales and Marketing too much there is a possibility that the product will diminish in quality and effectiveness.