: Google says they use "many things" to determine page rank. I think it is a quite reasonable leap to believe they also use certificate authenticity. If so, because a self signed certificate

Google says they use "many things" to determine page rank. I think it is a quite reasonable leap to believe they also use certificate authenticity.

If so, because a self signed certificate is not as trusted, this would probably hurt your page ranking. I'm guessing significantly hurt it.

Furthermore, even if I was able to find your page in Google, it is likely that TrendMicro (my preferred virus software) would by default block it when I tried to view it, putting up a big red notice, "This is a dangerous page".

Also it might be worth noting that not all well known CA signed SSL certificates are the same.

One free cert for example isn't verified as much:

"90.) Why are Class 1 certificates free? ... Since Class 1
certificates are domain and/or email validated only and the process is
performed mostly by electronic and automatic means, StartCom doesn't
apply any fees for this type of certification." (1)

And my credit card processing company says:

"You should buy an SSL certificate from a good certificate provider.
We recommend DigiCert — their certificates have very wide acceptance
(and in particular should work well on mobile browsers, where many
other certificate providers fall short). NameCheap is another good
option. They have slightly lower acceptance but their basic
certificates cost to ." (2)

It is interesting to note this StartSSL's FAQ page is NOT served by https, while Stripe's help is.

That being said, I use a self signed certificate for development and testing, which I think is the only appropriate place to use this type of certificate.

[Edit: I previously said that I thought the free certificates could not be used for credit card validation. I am now not 100% sure of this one way or another. It seems that free certificates may work some of the time, but not all of the time.]