What is an Opt In?
Opt-in is an explicit consent procedure from the permission marketing, in which the end user makes advertising contact recordings - usually by e-mail, telephone or SMS - explicitly must confirm. Its contrast is an opt-out procedure, which in many cases is legally inadmissible.
Prior to non-addressed advertising, consumers can protect themselves by notifying them of their mailbox ("no advertising"), which email, and other advertising distributors must observe. There is also the possibility for consumers to register themselves on the Robinson list.