Why?
The message is funny, but also says that they kept their promise for a simple, intuitive platform and that getting their product was an excellent choice that made your life much easier.

Where?
Rounds app

Why
Success message upon completion of the security check is very short, but also surprising, funny, conveys a true sense of cooperation. Also, it tells the users how they benefited: by having a secured account.

Why?
After giving feedback on one of the product new features, they say what it actually means: You just improved the feature.