Airbnb's convenience-minded tooltip

Airbnb's vacation rental marketplace has deeply disrupted the traditional hotel industry by enabling users to rent vacation places directly from one another. When facilitating user searches, Airbnb automates certain features like Instant Book to accommodate user convenience.

Why this is really good UX:

• Instant Book places offer convenience to users who need to book a place quickly and don't want to wait for the host's approval. By automatically turning the feature on in places where there's a large selection, Airbnb helps users achieve their goals—i.e. book a place—faster.
• The tooltip lets users know about the automatic application of the feature, so they can choose to remove it if they want to, giving them full control.
• By letting users know that they have “tons of homes available,” the tooltip boosts user confidence that the service can help find the right place for them.