Seems like more Business School 101- the easier you make it for people to give you money, the better off your business will be. Unfortunately, with my recent experiences, it seems like a number of the SSL certificate hawks haven't learned this lesson yet.
I was recently trying to order a wildcard SSL cert for our domain at work. I've been a die-hard Thawte customer for years, so I figured I'd go with what I knew. Apparently, to get a wildcard cert (eg, one cert for *.earthclassmail.com instead of one cert per unique host). Thawte requires you to use their online chat app to order wilcard certs for some reason, instead of just using their normal online ordering. OK, fine. They have a form to fill out to get a chat session (name, email, repeat e-mail)- I filled it out, only to be presented with "Sorry, no agents available- try again later". I have to re-fill the form out every time I want to see if there's an agent available. Oy. After about four tries, I decided to go to a Thawte reseller.
Turns out the resellers are nice and cheap, too (~half price)- the problem is finding one that will take my money! The first two I hit don't have online ordering (for any certs!). The next one has a broken form validator that won't accept any phone number I type in. Does anybody test this stuff?
I ended up going to RapidSSL- they resell Equifax certs. Less well-known, but as long as it's included by default in our supported browsers, I don't much care.
Moral of the story: Make it easy for me to pay you! We've always got more work we could do in this department as well, but we have spent significant effort on streamlining our signup process...