If you are considering establishing an e-commerce business, buy something from a small company to see what it feels like to trust an online business with your credit card number. Make notes of what works and does not work on sites similar to what you think you might want. You will also need to do some online marketing or hire someone to do it. A well designed site will load on all commonly available browsers. A web site should be attractive with pleasing colors and well done layout.
Good navigation makes it easy for users to find what they want.
They will not spend a lot of time on your site looking. No visible counter, needless animations or distracting backgrounds. Bleeding-edge technology requires knowledgeable implementation. If your visitors cannot download a page or get an error during download, they will go some place else. Most sales come from repeat orders, so exceed your customers expectations and bring them back for more.