There aren't any in my opinion. I don't know any webmaster who willingly puts his email address in an opt in list. I hate getting stupid emails announcing another new program. Any list you get will have loads of unsuspecting webmaster email addresses on it and you will only hurt your business.
This is just my opinion cuz I really hate fucking Spam... and even an email from someone who thinks they have a so-called "opt in" list is still fucking Spam in my book.
Sorry - I am in a rage tonight.
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Make $$$ the Diabolical Way