I feel like WeTransfer has got this right. They have wonderful full page ads and are monetizing by selling premium accounts to corporates, which have the ability to change the ads to fit their branding. https://wetransfer.com
WeTransfers user experience is great. I'm not sure the economics are ultimately going to work for them; the funding [1] gives them some runway, but they are already transitioning to more of a cloud storage provider. Simple utilities usually add bloat to drive value for premium plans. [2] In my experience, as they approach Google Drive and Dropbox in features, the product will bloat and become less functional and useful.
