Why It Matters
Sending email to someone who didn't opt in is spam -- legally and practically. Regulations like GDPR, CAN-SPAM, and CASL all require some form of consent before you can email someone. Beyond compliance, opt-in lists dramatically outperform purchased or scraped lists. You'll see higher open rates, fewer complaints, and better deliverability because you're emailing people who actually want to hear from you.
How It Works
There are two main flavors:
- Single opt-in: The subscriber enters their email and immediately starts receiving messages. It's frictionless but lets typos and fake addresses slip through.
- Double opt-in: After entering their email, the subscriber receives a confirmation email and must click a link to verify. This adds a step but ensures the address is real and the person genuinely wants to subscribe. Double opt-in lists typically have 20-30% fewer subscribers but significantly higher engagement.
Quick Tips
- Use double opt-in if list quality matters more than list size (it usually does)
- Make your signup forms clear about what subscribers will receive and how often
- Never pre-check opt-in boxes -- that's not real consent, and GDPR explicitly prohibits it