One of the biggest mistakes made with any online company, is not following through with the services and products they offer on their website. For instance, when you provide a software, its a simple notion that you have to provide documentation for the software that matches its performance. This also means the software has to perform just like you say it will. The same applies for any service you provide. A mistake that is made time and time again by many companies is not updating the content of their website, or the documentation of their products.
When customers purchase a product from a web company, it is the same as any other binding contract. Companies that do not follow through are obliged to refund any purchases they do not honor. For a dose of common sense, realize this is a direct violation of any business model.