Conversions are recorded when:
A user views a story within a 7-day window and purchases an item. This purchase is recorded as a view-through conversion.
A user views a story, and clicks on a story widget within a 7-day, and then purchases an item. This purchase is recorded as a click-through conversion.
Note that click-through conversions have priority over view-through conversions.
Example: if a user views a first story and completes a purchase then visits your e-commerce store again within a period of 7 days and views a second story, clicks on a story widget and completes a purchase again. This purchase be recorded as 1 click-through conversion.