You're already gonna be encouraged to move to an Enterprise ($5k+) account if you use too many resources, and/or if too much of your traffic is from non-browser

You're already gonna be encouraged to move to an Enterprise ($5k+) account if you use too many resources, and/or if too much of your traffic is from non-browser clients, and probably for a bunch of other reasons I don't know about it. The terms under which this may happen are essentially arcane knowledge learned through experience. Think about it: if this weren't the case, every other CDN would already be out of business, rather than rapidly expanding and acquiring and growing. Plus, you don't get an SLA for any of their "self-serve" plans until the $200/month one.