Overter is a financial services company that does not sell products or services on Amazon. They are running a campaign on Amazon promoting a new credit card, where the ad directs users to an enrollment page off of Amazon. What type of campaign is this?

This is a "link out" campaign because the ad directs users off of Amazon to an external website (the credit card enrollment page). Amazon DSP campaigns are categorized as "link in" or "link out" based on whether the ad's destination is within the Amazon ecosystem or an external site. A "link in" campaign would direct users to a product detail page or store on Amazon. Since Overter does not sell products on Amazon and is promoting a service with an external landing page, it clearly fits the "link out" definition.