When to use
An NBA shows the most relevant action in a specific time frame. The time frame plays an important role - based on our data and prediction model we display the action that a user is most likely to perform. Therefore, an NBA is a dynamic component and its content can change from one moment to the other. It should only be used for this purpose.
The type of NBA (primary or secondary) depends on context. In general, a primary NBA is used when there is just one NBA to show, unless there is another primary action (button) present.
Layout and positioning
Because its intended high relevancy, an NBA is usually presented at a prominent position on the page or within a specific section. An NBA should occupy the full width of the containing element to make it stand-out.