> ⇒ I think it’s more of “we were looking for a new revenue stream, and picked this as a way to get that”

This seems highly implausible given the 2 USD/mo pricing, the existence of a free storage plan, and the non-negligible operating costs that obviously do exist.

I'd be interested if you have data that supports the idea of the economics working out though.

I do not have data, but I do have arguments.

If the economics do not work out, why did they chose to create infrastructure and take on the burden of supporting it instead of implementing backups to the popular cloud providers, and not having that extra operational burden?

Also, iCloud gives individuals 2 terabytes of storage for $11 a month. OneDrive and Google Drive are similar. S3 is less than 3 cents/gigabyte (with extra costs for reads and writes)

I guesstimate backups will take less than 100GB per user. At Apple’s consumer pricing that is slightly over half a dollar.

So, if they buy storage at bulk and get a sufficiently high number of customers, I do not see why they couldn’t make money on $2/month.