The actual purchase of a mailing list along with the rights to mail it directly. Permission can only be “sold” if the subsequent mailings continue to match the frequency, brand name, content, and “from” of the past owner’s mailings — and even then this is a somewhat shaky procedure on the spam-front. You are in effect buying a publication, and not just a list.

Building a Highly-targeted Opt in List: When Money Lies Beneath the Lists
Are you successful with your Internet business? Better yet, do you think you are successful with your online business? When most online entrepreneurs are asked with these questions, they often brush it off.