The nickel version: Honesty truly is the best policy!  In my opinion, I feel that the best way to be sucessful and increase sales is to accurately outline my listings in a clear and concise manner and respond to customers' emails in a timely manner.  Even if your turnaround time for shipping isn't quicker than someone else's that sells a similar product, don't be untruthful.  Most feedback is based on shipping-don't indicate you'll ship in one day, when you know you need three days.  People can tell when packages are mailed and no one likes to be deceived.  If something unforseen happens where you cannot ship your customers product within the specified timeframe, just let them know.  It will be appreciated if you're upfront and honest with your customers.  If you are honest and be as detailed as possible about your item, people will keep coming back, refer others to you and leave great feedback.