Your existing email contacts are a built-in pool of subscribers who already know you. Purpose-built emails invite them to join your text list, and because they're already engaged with your brand, conversion tends to be strong.

Use this a few ways: run a dedicated "join our texts" campaign to your full list, add a text-opt-in invitation to your welcome or onboarding series so new contacts get the ask early, and keep a standing CTA in your email footer of each email. Targeting your most engaged email subscribers first usually produces the best opt-in rate.