There are a few ways to do this:
  1. Before you publish the store, associate the products with a particular interest (step 12 when editing the product). Then you can use the interest opt-in groups to identify constituents who purchased that item.
  2. Create a query and use an interaction clause:
    1. Go to Data Management > Query
    2. Click on "Create a new query"
    3. Give the query a name and description and save
    4. Click on "Add an interaction clause"
    5. Choose "Referenced Types" and then "eCommerce purchase" as the type
    6. Pick the name of your eCommerce store and save
  3. Run an eCommerce Purchasers Report