This package connects to an external virtual shop (Virtuemart 2, Magento 1.7 and Prestashop 1.5) and publishes its categories and products through a Concrete5 native block. 

There is no importing/exporting process: All data (categories and products) are served and refreshed  "on the fly", while the user is browsing the Concrete5 block. 

You can use VM or Magento control panels to update your catalog