Background: I am building a commerce digital download product site. I stumbled upon the website themeforest.com (by Envato). It is a wordpress site. Anyway, they sell licenses to content and the ability to download that content once purchased, much like the Commerce File does within Drupal Commerce.
ok now my question: They have a cool function that when you are on a product page and you have already purchased that product (and you are logged in) a block shows up that says "you have already purchased this item, download it here."