This is the objective you use for ads that automatically show items from your catalog based on your target audience
Rationale behind Catalog Sales Campaigns:
This type of campaign is used to great effect to re-target people who have looked at certain items on a website, but not actually bought them. They can be shown the same item, or complimentary items as a jog to revisit and complete the purchase.
How Facebook chooses the people it shows your Campaigns to:
Facebook will show your ads to the most suitable people that it thinks will purchase – however you can affect this in your targeting by ensuring that you eliminate people who have already purchased a particular item. You can also use a longer retention window, and segment your audiences by the amount of time since they visited your site.
Download our full Facebook Ads Cheat Sheet here. Includes complete list of the Campaigns and Audiences.