There is a really great module that was developed by Jared Howland at BYU that allows for Omeka-S users to use cloud services as a back-end for their Omeka sites. This module makes it easy to use something such as an AWS bucket for storage of large media objects that are being uploaded to Omeka.
We have found this useful for some work in DH that faculty are doing with archival quality scans of comic books or photographs. These are projects that would normally eat up allocated space on a web server fairly quickly. In something like our instance of Domain of One's Own, a shared webhosting platform, our faculty are only given 1GB of space by default. In a project like these above we would find the allocated space being consumed within about 5-6 uploads. This module allows us (for a reasonable price using our campus contract) to use AWS as the back end for these projects. We don't have to provision an additional space for them, they can use their own domain space for it without using up all of their space.
Tutorial is in development at: