The most important factors influencing conversion rates are:
• Is the transaction process clear? Do you have a good call to action that encourages people to follow through? Is it an obvious path or are you losing people along the way?
• Does your site look reputable and trustworthy? People are not going to go through with the transaction if your site looks amateurish or in any way dubious. Do you have a physical contact address given?
• Are you sure you've judged the market right? Does your product give good value for money? Is this evident on your website? How confident are you that there is demand out there that you aren't tapping into?