For selling any product first its always important to do the need analysis of customer. for this you need to listen the customer very carefully. once you done with this you know what exactly what customer is looking for.
After this you need to match customer's requirement with your product. try to tell each and everything very carefully explaining how the product fulfill all his requirement. In between if customer ask anything do not ignore his question. First answer that question and again continue from the point you where interrupted.
this will give a very good impact on customer and he will feel satisfied and happy. :-)
