Ah, I should have emphasized that I host mostly for non-profits and personal blogs. In those cases, revenues from ads make little difference. I cannot sincerely say I have noticed a drop of revenues from ads on the websites I host at DH with CloudFlare, but I can imagine it might make a difference if you are used to earn thousands of dollars.
As for the many “complaints” from “other webmasters”, I did bother to read many of those, following up some of the links you posted, and the truth is that the vast majority of the complainers fit into one of two categories:
- They are clueless about how to configure CloudFlare properly and complain because they clicked on the wrong buttons… without understanding what they were doing (e.g. layer 8 error).
- They have opposite policies than CloudFlare (i.e. they do not mind less security, more DDoS attacks on their websites, but they find it horrible that their visitors get an extra cookie and/or the very occasional CAPTCHA to verify that they’re human). In this case, their complaints are certainly justified, specially because it’s not so obvious how much extra protection CloudFlare is putting on top of your website (much of which cannot be turned off) without testing first.
So maybe my enthusiasm about CloudFlare should be curbed: you should definitely try it out first for yourself, see if it does what you want, see if their policies are in tune with your own, and only then use CloudFlare if you think that the benefits outweigh the minor inconveniences.
I would gladly say that CloudFlare should be appropriate for more than 90% of the cases. It’s the remaining 10% which will prefer a different solution.