Over at the popular networking site LinkedIn one fella asked a very thought-provoking question — "What are [the] top three 'sins' of a startup, from your experience, one should avoid?"Here are some answers, in no particular order:- Failure to clearly define target customers- Not understanding your profit and cost drivers- Not having a clear purpose and vision of the company- No strategic business plan for success- Chasing the dollar vs. your passion- Too much debt starting out- Knowing the difference between making a mistake and adjusting one's course- Believing that the best technology will win- Underestimating the implications of your risks- Procrastinating- Failure to hire or retain top talent- A great accountantMy top sin is not defining your target customer. One should always ask, "Who and why would anyone want my product or service?" before proceeding. Debt control and a detailed strategic plan are important success indicators as well.What do you think are the top sins when starting a new business? What specific actions can help prevent one from committing them?