What action triggers a charge for a Shopping ad?

When a Shopping ad is clicked, it triggers a charge because this action indicates that the user has shown interest in the product being advertised. In this context, the charge is primarily associated with pay-per-click (PPC) advertising models where advertisers pay only when a user clicks on their ad and is redirected to their website. This click generates a valuable opportunity for the advertiser to potentially convert that interest into a sale, making it a critical metric for measuring the effectiveness of the ad campaign.

The other actions, such as making a purchase, viewing the ad without engaging, or simply searching for an item, do not directly incur costs associated with Shopping ads in this model. A purchase may not always be linked with direct ad charges, as it may result from multiple impressions and clicks. Viewing an ad without interacting does not constitute engagement, and searching for an item does not imply any financial transaction with ads, as it is merely a query without additional actions. Thus, the click on the ad is the specific action that initiates the charge in the context of Shopping ads.