If you are selling physical goods, you'll need to consider how you're going to ship them. PayPal and other processors have worked with shipping merchants, including USPS and UPS, to offer one-stop postage processing. You will also need to research your state laws to determine if you are required to obtain a permit for selling online, or if you need to collect sales tax for your state or municipality.
Ecommerce allows consumers to electronically exchange goods and services with no barriers of time or distance. Electronic commerce has expanded rapidly over the past five years and is predicted to continue at this rate, or even accelerate. In the near future the boundaries between "conventional" and "electronic" commerce will become increasingly blurred as more and more businesses move sections of their operations onto the Internet.
BigCommerce is most easily compared to Shopify. Both platforms offer a similar experience when building an ecommerce platform. Like Shopify, BigCommerce offers a range of prices and packages tailored to different types of businesses. The platform is highly customizable if you are comfortable with some light coding. It is also possible to use themes and templates to build your website, but some of these will come at an additional cost.