> Did they figure something else out that nobody saw?

I may not have a full scope of the history, but my own experience with DDoS protection was quite different. Whilst providers offered anti ddos protection through GRE tunnels and dedicated machines behind DDoS appliances and a heavy null route hand, Cloudflare had a simple few-click solution that worked at the web application level making things a lot easier and, also, allowing for features like caching, and thus, CDN benefit from a global network. Further, they've maximized performance on their machines, and as a result, Cloudflare is wicked fast.

Cloudflare does what it does really well and has built additional services on their global network that make a lot of a sense and provide a lot of value.

Hats off to CF.