We are concerned that the terms opt-in and opt-out can be misunderstood. Marketers have traditionally favoured the latter, that is, where the default (an unticked ‘opt-out’ box) indicates a failure to register an objection. The fact that someone has had an opportunity to object which they have not taken only means that they have not objected. It does not mean that they have consented. We also note that the terms subscribe and unsubscribe are commonly used to indicate agreement or objection.
By itself, failing to register an objection will be unlikely to constitute valid consent. However, in context, failing to indicate objection may be part of the mechanism whereby a person indicates consent. For example, if you provide a clear and prominent message along the following lines, the fact that a suitably prominent opt-out box has not been ticked may help establish that consent has been given. For example:
'By submitting this registration form, you will be indicating your consent to receiving email marketing messages from us unless you have indicated an objection to receiving such messages by ticking the above box.'
In summary, the precise mechanisms by which valid informed consent is obtained may vary. The crucial consideration is that individuals must fully appreciate that they are consenting and must fully appreciate what they are consenting to.