I am currently working with a company that has a great email program. All email addresses are triple opt-in. Guaranteed 3% click-thru on email sent. I have been using them for a while and for the money I am getting way better conversions than my ppc was doing. If you would like more information let me know.
I don't see the purpose of opting in more than twice, that is more or less a referendum that they know what they are getting into.