Klaviyo + Postscript SMS for Black Friday + Cyber Monday surge?

Klaviyo is the de-facto email + segmentation platform for DTC; Postscript is the leader for SMS. Both have official Magento integrations. The toy + game BFCM flow pattern:

• VIP early-access flow, tagged segment (last-12mo customers + LTV > $200) gets the BFCM deal 24h before public. Klaviyo trigger + Magento customer-segment-based pricing rule.
• Abandoned-cart recovery, 1h / 24h / 72h email + Postscript SMS. Q4 cart-abandon rate runs 75-82% on toy stores; aggressive recovery (with a $5 wrap credit) lifts recovered revenue 8-12%.
• Back-in-stock alerts, native Klaviyo + Magento integration. Customer signs up for a sold-out SKU, gets email + SMS the moment Magento stock goes positive. Critical for Pokemon TCG, Funko chase variants, Lego anniversary sets that restock multiple times in Q4.
• Last-day-cutoff push, Dec 15 / 17 / 18 / 19 / 22 segmented sends ("12 hours left to order for Christmas delivery via FedEx Ground"). Drives 6-15% of Dec 14-22 revenue on stores I’ve measured.
• Post-purchase wrap upsell, if cart didn’t include gift wrap, post-purchase email offers it as a $4 add-on with a 24h window before warehouse picks. Magento order-amend API + Klaviyo trigger. Lifts wrap attach 8-14%.
• Q4 newsletter cadence, weekly through October, twice-weekly Nov 1-Black Friday, daily Black Friday week, daily through Dec 22. Postscript SMS once-weekly through November, twice in Black Friday week.

Magento + Klaviyo native sync handles customer segments, order history, abandoned carts, browse abandonment, and back-in-stock. Postscript Magento extension does SMS subscriber capture (cart drawer popup, popup on category) and triggered sends. ~$150-$1,500/mo combined depending on subscriber count + send volume.