When you interact with Dropbox, you will always feel delight (even in the cancellation page). More companies are following on its footsteps to think of brand, product and services as a symphony, not just silos. Gone are the days when brand was just about the logo and messaging. We are in an era where if these 3 don't work together, there is no delightful user experience.
These are exemplary pioneers in this space. Note: brand should never be just "injected" into the product, otherwise, it will come across an inauthentic and broken.
Read: Finding Clarity & Energy