
Your Instagram followers are not yours: the platform can change its rules or lock the account. Your email list and the numbers of people who agreed to hear from you are yours.
Never add anyone to an email or WhatsApp list without their clear consent, and never buy ready made lists. Explain what they will receive and how often, and make leaving easy. Privacy and messaging law differs from country to country, so check your country’s rules and the WhatsApp Business terms.
Write the three welcome messages. Put a simple sign up form in your store or bio, with one line under it explaining what subscribers will receive.