Service that matches email addresses to a database of personal names and postal addresses. Appending may require an “OK to add my name” reply from the subscriber before you can add the name to the 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.