I don't think it really matters how big the actual market it, what matters is being known for having such solutions. Even if the majority of customers don't hav

I don't think it really matters how big the actual market it, what matters is being known for having such solutions. Even if the majority of customers don't have the service, as long as they know it exists, they'll prefer Amazon vs competitors because they'll feel like they're supporting a company that cares. Personally, I think it would be great if these reusable packages optionally came in a package that has a digital lock that can only be unlocked through the app (i.e. public key crypto over Bluetooth/NFC). This would make them look like the secure option as well as the green option. It can even operate at a loss and probably still be beneficial by driving more purchases their way.