How do the viewed products stats work?
They display the number of products displayed on your customers' computer screen.
Although the products are rendered in the app widget every time the app loads in your pages, they may not be in the visible part of the page.
Once they become visible because, for example, the user scrolls down the page, they are counted as viewed.
Please note that this doesn't mean that the customer really viewed them, only that they appeared in a visible part of the screen.
A product is counted every time it appears on the customer's screen but only once per page loading. If the app is reloaded, it will be counted again.
Repetitions are not excluded, a product is counted as many times as it is displayed.
If you have many products rendered but not many products viewed you can consider placing the app widget in a more prominent position.
Technical note: a product is considered viewed when its image totally fits inside the browser viewport (i.e., the visible area of the page), even if it is hidden by other elements.