With permission based email marketing you will obtain permission from your email recipients before advancing to the next step in the purchasing process. For example, you will ask permission to send email newsletters to prospective customers. It is mostly used by online marketers, notably email marketers and search marketers, as well as certain direct marketers who send a catalog in response to a request.

This form of marketing requires that the prospective customer has either given explicit permission for the marketer to send their promotional message (like an email or catalog request) or implicit permission (like querying a search engine). This can be either via an online email opt-in form or by using search engines, which implies a request for information which can include that of a commercial nature.

Once they give you permission, they are considered "Opted-in".

Marketers feel that this is a more efficient use of their resources because the offers are sent to people only if actually interested in the product or service. Not to mention they need to get prior permission to comply with spam laws.

Permission marketing is now a large-scale activity on the Internet. A leading Internet business periodical noted that "permission marketing was once a niche business. Now, everybody is doing it.