Anyone who wants to sell (digital or physical) products online.
There are lots of benefits to building an E-Commerce Website:
This is by no means an exhaustive list and they are large established options.
This is the best option if you have an existing WordPress website and want to add e-commerce functionality to your website and have ruled out transitioning to another platform. This is not an e-commerce platform, it is a plug-in for WordPress websites.
Keep in Mind: If you don't already have a WordPress website, it's better to stick to an all-in-one platform than go this route.
This system is free, however it is not the most intuitive experience for store owners and requires a much more "hands on approach" to ensure everything works properly. Even though it is free, many of the integrations, themes and add-ons are not.
Unless you are already on WordPress and are not willing to move to another platform I do not recommend this as it is not intuitive and almost requires more work if you are not familiar with WordPress.
Shopify is by far the best mid-range e-commerce platform for most small to mid sized businesses. Its market share, platform stability, security and community of experts makes it a solid and reliable primary e-commerce option.
Shopify is a challenger to Amazon every day.
Though some features take some help customizing, it has a massive suite of hosted e-commerce features that help merchants sell on-line, in-sore, and on multiple distribution channels (think: Amazon, Facebook, Instagram, Pinterest, Wholesale, etc).
Since Shopify was built as an e-commerce solution and did not "back into" selling online, it is positioned to help merchants sell safely, securely and easily. It comes with a Merchant app, handheld POS and integrates with an iPad terminal for in store sales and inventory management.
Like WooCommerce Ecwid is an e-commerce platform that integrates with your existing website. It is relatively easy to implement with sites like Wix, Webflow, WordPress, Squarespace, etc. If you are looking to add a few products to an existing site, where online sales is not at the core to your business model, then Ecwid is a great choice.
They do have an all-in-one website builder; however, there are better site builders out there that will give your more bang for your buck. I only recommend Ecwid if you are adding it to an existing website.
If you want a stand alone builder, have a larger number of products or your website's primary goal is online sales, I'd suggest Shopify.
However, if you already have a website, want to add in e-commerce functionality and do not want to rebuild, then Ecwid is a great option.
If your website's primary focus is online sales and this channel is a top priority to your business model, then Shopify is the best and most reliable option that will grow with you as you expand your operation.
If you have an existing website and want to add some additional e-commerce functionality then I suggest WooCommerce for Wordpress users and Ecwid for anyone else.