Came here to say something like this. While the site is a bit of a pain, and the certs are free, make damn sure you have your site configured the way you want it before you generate the certificate.
It's $25 to revoke a cert, i.e. free up the name so you can use it again elsewhere. I used part of my domain name for an XMPP cert that I later wanted to use for a web subdomain with the same name.. nope. Stupid.