Detailed web event telemetry is where I have seen the "biggest" data, not application-generated data. Orders, customers, products will always be within reasonable limits. Generating 100s of events (and their associated properties) for every single page/app view to track impressions, clicks, scrolls, page-quality measurements can get you to billions of rows and TBs of data pretty quickly for a moderately popular site. Convincing technical leaders to delete old, unused data has been difficult; convincing product owners to instrument fewer events is even harder.
My idea is for everyone to have their own personal website/app/space (could be very basic, prebuilt templates, drag and drop, something your grandparents could set up). That would then lead to the development of social networking protocols or being able to subscribe to web content modules. Basically, I want RSS feeds for web components/modules, but then a personal portal to interact with the items i subscribe to.
I, as userA, with site www.squarespace.com/userA, could subscribe to all or part of userB's site www.wix.com/userB or www.userB.com/photos but not www.userB.com/crazyBlog. Then, on your own site/app, you choose the things you are subscribed to that you want to "re-publish" or add comments to or share. userB could also choose to not let you follow their space.
This decentralizes away from any particular company and should limit the unintentional crazy that is broadcast across current platforms.