The process of removing identical entries from two or more data sets such as mailing lists. AKA merge/purge. Delivered email:  Number of emails sent minus the number of bounces and filtered messages. A highly inexact number because not all receiving ISPs report accurately on which email didn’t go through and why not.
Building Your Business with an Opt-in List
Before revealing the secrets of the trades, here are myths and fallacies that need to be cleared before one indulges into building an opt-in list.
