That’s for the CDN. It’s about serving static, cached content faster. I actually tried to pay and use their Stream service, but it’s only to be used for serving video in a when page. While they’ve not directly clarified on the topic (even after being asked directly in the forums several times), don’t turn on caching and it appears to serve the language they’ve used in the updated TOS. I’m not a lawyer here, but parse that all as you will. Don’t take up storage on their CDN and they seem to be happy. I actually did buy some domain names through them to make sure I’m not just using their services without giving anything back. But, that’s a matter of conscience.