Why are we harping on this USP thing again? Because many business owners still don't get it. If you do not have a USP, you have nothing to differentiate yourself from other competitors or similar businesses. So you do not give your potential customers a good reason to deal with you instead of the other "me-too" businesses out there. If there's no difference, they might as well throw darts to decide who to give their business to.

You can read up on the USP at this link: http://www.fastf.com/usp.htm