There are already a bunch of awesome plugins that let you bring your store online. You will still have to promote your store aggressively and provide your customers with incentives and triggers to achieve more sales. WordPress eCommerce Notification is a handy plugin that lets you display what others are buying on your site.
This plugin should work with most themes. It is mobile friendly. You can customize the message displayed to your customers. Admins can set up notifications to attract attention to new or special deals. They can also change time, sound, colors, and other settings.
villatheme is behind this interactive plugin. You can find out more about it here.