SMS averages 98% open rates and 30% click-through. Dramatically higher than email. The catch: it requires explicit opt-in (TCPA in the US, GDPR consent in the EU).
Cart-recovery SMS recovers 4–10% of abandoned carts on average; voice + SMS run together typically doubles that.
SMS shines as the follow-up channel after a voice call goes unanswered, with the saved cart link or appointment confirmation.