When sharing preferences with businesses, you must also give them permission to contact you. Signing a form or clicking a button on a website to confirm permission is an opt-in.
Opting-in is important because many governments have created rules to protect their citizens from unwanted communications (including the United States). Because of these rules, businesses need you to opt-in before they can email, text or call you.
For example, let’s say you want emails about coffee from your favorite roaster. On their website, you select the email newsletter you want to receive, enter your email address and click to opt-in, confirming that you want to receive emails.