Airbnb's book instantly feature announcement

Airbnb’s Instant Book feature announcement follows a classic 'modal into tooltip' UI pattern. This UI pattern captures a user’s attention upon login, describes the new feature’s benefits, and then shows the user how and where to identify it.

Transparent background modal window.

Tooltip marking the features location.

What we like: the transparent background modal window doesn't distract users from their end goal, and the content inside the modal is relevant and informative. Once inside the app, the tooltip is appropriately placed and briefly descriptive.