One of the powerful tools in online “email” marketing is to build an opt-in mailing list. An opt-in mailing list is a database of peoples’ names and email addresses that have subscribed to an email list via a web form giving that list owner permission to send them periodic emails on the topic they are interested in. The best gift of this powerful tool is the possibility of being able to talk to people who are particularly interested in your product, service or organization.

This gaining popularity of building opt-in mailing list is known as Permission Email Marketing.