There are more features available if you pay a fee, but you can get some goodies even with the free option. All of this is easily achieved, once the set up and the features are chosen, by altering the DNS servers associated with your domain and by pointing them to the Cloudflare's DNS servers. Once this is done, you simply tell Cloudflare of the change and wait for the DNS propagation to take effect.
Although there is not much explanation on what is being done technically to meet such amazing results (how often do you hear that you can get the equivalent of a CDN for free?), I am now attempting to confirm Cloudflare's claims with my own measurements. In fact, if you peek into their management dashboard, you can reach a summary analytics panel which tells you how many bad requests they have filtered and how many requests / bandwidth have they "saved" you from actually having to serve! So far it seems that they saved me 40% of the bandwidth and above 60% on the number of requests... which would be pretty amazing if I can back it up with my own measurements!
I am not sure if further details can be found or requested from them, maybe once you are a paying customer? After all although my blog is simply a 'divertissement' I can easily figure out how a professional firm may want instead to have full control over this process and know exactly, for instance, what requests have or haven't been filtered, or what content is being cached and exactly for how long, and what the purging strategy is! Think about it, there is no much damage done if one of my posts doesn't display the latest revision or comment added, but this would be different if one of your product pages the customer is seeing is out of date and does not display the latest special offer you've just set up!
Far from formulating my conclusions, I'll reserve myself the right of playing with this service a bit more and see how it pans out! I have to say that so far the set up was painless (even my grandma could have probably figured out the steps herself) and straightforward.
Do you use Cloudflare? Any experience of yours to share? Feel free to use the comments section!