Definition

Opt-in is a form of marketing given by users of a website to confirm their interest in a product or service. For example, opt-in forms include signing up to email and mailing lists, agreeing to the use of cookies, and agreeing to legal policies. Under EU law (both GDPR and the Cookie/ePrivacy Act), even if people give consent, they have the right to opt-out and should always be informed of how they can do so. There are two types of opt-in, single opt-in means that the user only has to opt-in once and starts receiving advertising messages , for example via emails. But a double opt-in means that the user has to opt-in and then confirm their email via another link.