Opt-In

Giving your credit card company or bank permission to include you in a particular service.

Opt-in email marketing means sending marketing messages only to people who explicitly requested them. If a customer asks for a specific piece of information, you have the permission to send that information and nothing more. To continue sending marketing emails you need the explicit permission to do so ("Please send me announcements and special offers via email", for example). Also note the difference between single opt-in and double opt-in. Also Known As: Permission-based marketing).