Ecommerce, or shopping cart web sites, have become a popular shopping alternative for consumers, who buy everything from books to clothing to automobiles to pet toys using the internet and online shopping. What is ecommerce and why do you need it? To put it simply, ecommerce is the buying and selling of goods on the internet. You might think that the arena of ecommerce is only for big businesses, but today many small and medium businesses are very successful at selling their products locally, nationally, and globally.