Our website stores a lot of user generated content in the forum of images and attachments. Before Leadwerks Game Engine was on Steam the demands were even higher, since we had our own downloads and gallery sections that stored data on our server. Since the implementation of Steam screenshots and Workshop a lot of that has been offloaded onto the Steam servers, relieving our server from some of the data storage and transfer costs. (If you're interested, all our old content is archived on Google drive here.)
Currently our website weighs in at about 35 GB of data. This is backed up online daily, and offline about once a month. The entire server is usually burned onto a Blu-Ray disc and saved away. The time and storage space this takes is considerable, and as the site keeps growing this approach will not be sustainable.
Amazon S3 allows you to store files in the cloud with an API to write and save files, at a cost of $0.023 (that's 2.3 cents) per GB per month. I've hooked into the service to offload all user attachments, images, and profile pictures onto Amazon's servers. This leaves our core site data at an easily manageable 2.5 GB, which I can easily burn onto a DVD.
Now that all user data is stored in the AWS system for dirt cheap prices, we can easily grow the amount of content on our site without it impacting the site responsiveness, backup time, or having much impact on operating costs. Stay tuned and I will tell you how we are going to use this for game development.