The CloudFlare free tier service offers unlimited bandwith while other CDNs charge starting at about $.10/gb.
CloudFlare does not have bandwidth limits. As long as the domains being added comply with our Terms of Service, CloudFlare does not impose any limits.
There's very little said on their website in the way of restrictions. The offer appears to be legit.
Is there a catch? If not, why aren't all other CDNs out of business?