Ads on the marketplace goes by Cost-Per-Click (CPC) bidding model by default. This is the easiest way to leverage on the marketplace and no technical requirement is needed.
Listing ad on the marketplace is free. If there is no click on the action button to visit the landing page or engage with the product, there is no charges at all.
We've also introduced a Enhanced CPL/CPA bidding model (also known as Premium Hybrid) for more IT savvy advertisers who would like to pay per lead and able to do conversion tracking. Running Enhanced CPL/CPA Ad Campaign requires advertiser to setup conversion tracking, please contact us for assistance.