The attribution model consists of three conversion types:

1. Direct.
   After an advertisement is clicked on and the article is subsequently purchased.
2. Secondary.
   An advertisement was clicked on and this led to the purchase of another article from the same advertisement campaign.
3. Tertiary.
   An advertisement was clicked on and this led to the purchase of another article (from the same partner), within the same category.

The period in which this is measured is 15 days.