Amazon was a 20 year old company before it was reliably profitable by accounting metrics. Is their business model viable? That's how a growth company works.
I don't think that's true. Snap's and Twitter's consumer-facing product is free, while Dropbox charges for theirs.
They played the long game here. I'm still not a paying customer after almost ten years (partially because I got a lot of free space via referrals and trying out their apps). But if I ever max it out and decide to start paying someone for space, it'll be them unless there's something out there that does what they do at a price that's low enough to make the effort to switch worthwhile.
And, more notably, the freemium model means that they're able to invade the business world in the same way that the iPhone did with BYOD. And there's a lot more money there.
I'd be stunned if Dropbox wasn't very successful already, and I'm happy that someone outside of the Big 5 is doing what Dropbox is doing. It's a fantastic and indispensable product for me.
Amazon’s decision was quite obviously a choice. Snap and Twitter are more natural comparisons for Dropbox if it’s still unprofitable.