If you're planning on selling a product, look for a web host that offers a Secure Sockets Layer (SSL) certificate, because it encrypts the data between the customer's browser and web host to safeguard purchasing information. You're probably familiar with SSL; it's the green padlock that appears in your web browser's address bar as you visit an online financial institution or retail outlet. A few companies toss in a SSL certificate free of charge; others may charge you roughly $100 per year for that extra security layer.
One thing we learned in reviewing the services listed here (and many more) is that even though the packages are very similar, they are not identical. Some are more security-focused than others, offering anti-spam and anti-malware tools. Others offer a variety of email marketing tools. While most of the hosts we've reviewed have built-in e-commerce, you may want to consider using a more-robust third-party online shopping cart application like Shopify instead.