From emma: It seems as if every list out there can be considered somehow permission-based, if you think about it just the right way. The question is, what does that mean? And while we’re at it, is there even a difference between a permission-based list and one that is considered opt-in? The very basic definition for both is that someone gave their email address to someone else. What we all need to be concerned with is to whom the address was given and for what purpose.