One of my clients wanted an E-Commerce solution for his website and after a little bit of analysis we opted for the community edition of Magento.
We wanted something based on the usual LAMP stack, that was OpenSource so it could be extended, was free as in beer, had great international support, was fully featured and enterprise ready, could pass PCI DSS compliance, allowed reasonable payment gateway options, could scale and was easy to extend as well as backup. Also we wanted complete control of the deployment, rather than integrating with a 3rd party cloud service provider such as Shopify to keep costs down and retain flexibility.