Appendix D: Opt-In and Opt-Out
The notion of permission-based marketing is significant to the mobile channel, especially in markets where the user is charged for each message or data transmission (or it is deducted from a quote for which they pay a monthly fee, which is essentially the same thing). In the US, some users pay a fee for each message received.
(EN: Not mentioned is that companies, or project sponsors, seem to fall into two camps. One camp is concerned with the potential negative impact of unsolicited marketing messages, in making customers less likely to purchase and even damaging the brand. The other camp is concerned with legal action that may be taken against them. Aside of the ethical differences, this has a significant impact on their decision-making.)
Opt In
The opt-in approach calls for the user to take an action in order to receive messages (either a one-time message or an open-ended acceptance for a stream of future messages). The user may send a text message to opt in, and should be sent a response acknowledging their decision and providing with contact information and a method to revoke their consent. In the case of a stream of messages, each message should contain opt-out information.
A "double opt-in" approach is used where the user sends a request to receive messaging, hen receives a response to which he must reply in order to be signed up. The same principles apply.
Opt Out
The opt-out approach sends users messages without permission, but gives them the ability to remove themselves from the list at any time. Specific instructions can be given, but the service should also monitor responses from users who send a message such as "cancel," "stop," unsubscribe," etc.