Sms Marketing

SMS Marketing

Overview

SMS marketing achieves 98% open rates and click-through rates 5–10× higher than email, making it one of the highest-performing direct channels for ecommerce. However, SMS is heavily regulated — TCPA in the US requires explicit written consent, and violations carry fines up to $1,500 per message. Dedicated SMS apps (Postscript, Attentive, Klaviyo SMS) handle compliance, opt-in flows, and 10DLC registration automatically. Custom Twilio implementation is only needed for headless stores.

When to Use This Skill

• When launching an SMS marketing channel alongside existing email automation
• When needing TCPA-compliant opt-in flows at checkout and via pop-ups
• When wanting to segment SMS campaigns by purchase history, lifecycle stage, or location
• When sending transactional SMS (shipping updates) vs. marketing SMS to different opt-in lists
• When auditing an existing SMS program for compliance issues

Core Instructions

Step 1: Choose the right SMS platform

Recommendation: Use Postscript for Shopify and SMSBump for WooCommerce. If already using Klaviyo, add Klaviyo SMS to keep campaigns and flows in one platform. Use Twilio only for headless stores where you need full programmatic control.

Step 2: Set up SMS opt-in

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Shopify with Postscript

1. Install Postscript from the Shopify App Store 2. Go to Postscript → Keywords and set up your opt-in keyword (e.g., "JOIN") — customers text this to your Postscript number to subscribe 3. Go to Postscript → Sign-up Units to add opt-in forms:

• Checkout opt-in: Postscript adds a checkbox at checkout automatically — configure the consent language under Settings → Checkout
• Pop-up: create a timed pop-up offering a discount (e.g., "Get 10% off — text JOIN to [number]")

4. Important compliance settings under Postscript → Settings → Compliance:

• Confirm the consent language is displayed: "By subscribing, you agree to receive marketing texts. Reply STOP to unsubscribe."
• Never pre-check the SMS opt-in box at checkout — TCPA requires un-checked by default

5. Go to Postscript → Flows to build automated sequences:

• Welcome series: triggered on opt-in — immediate welcome message + discount code
• Cart abandonment: triggered when Shopify detects an abandoned checkout (different from email; can send even without email)
• Browse abandonment: triggered by high-intent browsing + no purchase within 4 hours

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WooCommerce with SMSBump

1. Install SMSBump (now Yotpo SMS) from the WordPress plugin directory 2. Go to SMSBump → Settings → Compliance and configure the checkout opt-in field 3. Go to SMSBump → Automations to enable:

• Cart abandonment SMS
• Order confirmation and shipping update SMS (transactional)
• Win-back SMS (customers who haven't purchased in 60+ days)

4. For GDPR compliance: SMSBump includes a double opt-in flow for EU subscribers — enable this under Settings → Compliance → Double Opt-in

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BigCommerce with Klaviyo SMS

1. Install Klaviyo from the BigCommerce App Marketplace 2. Go to Klaviyo → SMS → Getting Started and complete the 10DLC registration (Klaviyo walks you through this) 3. Add an SMS opt-in field to your checkout via BigCommerce Admin → Store Setup → Checkout 4. Build SMS flows in Klaviyo → Flows — SMS can be added to any existing email flow as an additional channel

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Custom / Headless

For headless stores, use Twilio. Compliance must be built into your application logic:

import twilio from 'twilio';

const client = twilio(process.env.TWILIO_ACCOUNT_SID, process.env.TWILIO_AUTH_TOKEN);

async function sendMarketingSMS(phone: string, body: string, customerId: string): Promise<boolean> {
  // ALWAYS check consent before sending — never skip this check
  const consent = await db.smsConsent.findActive(phone, 'marketing');
  if (!consent) {
    console.warn(`SMS suppressed for ${phone} — no active marketing consent`);
    return false;
  }

  // TCPA: no marketing SMS before 8am or after 9pm in recipient's local time
  if (isQuietHours(phone, consent.zipCode)) {
    await smsQueue.add('send', { phone, body, customerId }, { delay: msUntilMorning(phone, consent.zipCode) });
    return false;
  }

  await client.messages.create({
    from: process.env.TWILIO_PHONE_NUMBER,
    to: phone,
    body: `${body}\n\nReply STOP to unsubscribe`,
  });

  return true;
}

// Handle STOP/HELP/UNSTOP via Twilio webhook — required by carriers
export async function handleInboundSMS(req: Request, res: Response) {
  const { From: from, Body: body } = req.body;
  const keyword = body.trim().toUpperCase();

  if (['STOP', 'STOPALL', 'UNSUBSCRIBE', 'CANCEL', 'END', 'QUIT'].includes(keyword)) {
    await db.smsConsent.deactivateAll(from);
    // Twilio also auto-handles STOP at the carrier level for registered numbers
  } else if (keyword === 'HELP') {
    // Required: explain how to opt out
    await client.messages.create({
      from: process.env.TWILIO_PHONE_NUMBER,
      to: from,
      body: `${process.env.STORE_NAME} alerts. Msg&Data rates apply. Reply STOP to unsubscribe.`,
    });
  } else if (['START', 'UNSTOP', 'YES'].includes(keyword)) {
    await db.smsConsent.reactivate(from, 'marketing');
  }

  res.sendStatus(200);
}

Important for custom Twilio implementations: Register your brand and campaign through the Campaign Registry (TCR) before sending. US carriers block unregistered 10DLC traffic. Twilio's console guides you through this under Messaging → Regulatory Compliance → 10DLC.

Step 3: Consent compliance requirements

TCPA (US) requirements — non-negotiable: 1. Opt-in checkbox must be unchecked by default at checkout 2. Consent language must appear adjacent to the checkbox (not in fine print) 3. Required consent language: "By checking this box, you agree to receive marketing texts from [Store Name] at the number provided. Message frequency varies. Message and data rates may apply. Reply STOP to unsubscribe." 4. You must honor STOP within 10 business days (dedicated SMS apps do this automatically) 5. No marketing SMS before 8am or after 9pm in the recipient's local timezone

GDPR (EU) requirements:

• Same opt-in standards as TCPA plus explicit consent documentation
• Provide a data export mechanism (consent record with timestamp, IP, exact consent language)
• Double opt-in is required for EU subscribers in many countries

All major SMS apps (Postscript, SMSBump, Klaviyo SMS) handle these compliance requirements automatically. If using Twilio directly, you must build this yourself.

Step 4: Campaign segmentation

The highest-ROI SMS segments:

In Postscript: build segments under Postscript → Segments using order history, purchase frequency, and LTV filters. In Klaviyo SMS: add an SMS step to your existing email segments — the audience targeting is identical.

Step 5: Measure SMS performance

Best Practices

• Separate marketing and transactional consent — customers who opt out of marketing SMS should still receive order confirmation and shipping texts; these are different consent types
• Never send more than 2–3 marketing SMS per week — SMS is the most intrusive channel; high frequency causes unsubscribes faster than any other channel
• Keep messages under 160 characters to avoid multi-part messages — emoji count as 2 characters and trigger UCS-2 encoding, halving the 160-character limit
• Always include STOP instructions in every marketing message — most apps do this automatically; verify it is there
• Register 10DLC before going live — US carriers block unregistered traffic; registration takes 1–2 weeks through your SMS platform

Common Pitfalls

Related Skills

• @email-marketing-automation
• @cart-abandonment-recovery
• @cart-recovery-sms
• @push-notifications
• @customer-segmentation

SMS Opt-In for Checkout Page

Problem/Feature Description

A direct-to-consumer apparel brand is launching a text messaging channel alongside their email program. Their legal team has flagged that their previous SMS list was collected improperly and they need to rebuild it from scratch with clean, provable consent. The compliance officer has made it clear that they must be able to demonstrate — in writing if challenged — exactly when, where, and how each subscriber consented to receive texts.

The team needs a checkout opt-in component for their React/TypeScript storefront and the backend logic to store consent records in a way that will hold up to legal scrutiny. They also serve customers in the EU and need to be able to produce a complete consent history for any customer on request.

Output Specification

Produce the following TypeScript source files in your working directory:

• SmsOptIn.tsx — A React component that renders the SMS opt-in field for a checkout form. The component should accept a phone number and a callback for when the user toggles the checkbox.
• consentService.ts — Backend service containing:
• A function to record SMS consent in a database (you can use a mock db object — no real database connection is needed)
• A function to export a customer's full SMS consent history (for GDPR data access requests)
• README.md — A short description (2–3 paragraphs) of the consent model used, explaining how it handles different consent types and what data is stored for audit purposes.

Inbound SMS Handler and Transactional Notifications

Problem/Feature Description

A furniture e-commerce company has set up a Twilio number for SMS marketing but customers have started texting back with a variety of responses — some trying to opt out, some asking for help, and some with general questions. Carrier guidelines require the company to handle certain keywords automatically and consistently or risk having their messages filtered. The customer support manager also wants to make sure that general replies don't get lost.

Separately, the operations team wants to send shipping confirmation texts to customers who haven't opted into marketing — they assume that since it's operational information and not a promotion, the same rules don't apply. The engineering team needs to implement both pieces correctly: a webhook that handles inbound messages according to carrier requirements, and a transactional notification sender that plays by its own distinct rules.

Output Specification

Produce the following TypeScript source files:

• inboundWebhook.ts — An Express-style POST handler (/api/sms/inbound) that processes inbound messages from Twilio's webhook. You can mock db, supportQueue, and process.env values.
• transactionalSms.ts — A function that sends a shipping notification SMS, using a mock db and Twilio client.
• README.md — A short explanation (1–2 paragraphs) of how inbound keyword handling works and how the transactional consent model differs from marketing consent.

Use TypeScript. No real database or Twilio connection is needed — mock the external dependencies.

Promotional SMS Campaign Sender

Problem/Feature Description

A mid-sized e-commerce retailer wants to run flash sale campaigns via SMS. Their marketing team sends promotions to thousands of subscribers at a time, and they have run into problems in the past: some customers complained they received texts at 6am, a carrier blocked a batch for violating rate limits, and their legal team is concerned about messages sent to customers who had opted out weeks earlier.

The engineering team has been asked to build a reliable, compliant campaign sender that handles all of these edge cases automatically. The system needs to work with Twilio, respect when customers can legally be messaged based on their location, and not overwhelm the carrier. Detailed records of every message sent are required for compliance audits.

Output Specification

Produce the following TypeScript source files:

• smsSender.ts — The core send function that sends a single marketing SMS to a subscriber, plus any helper functions it depends on (timezone handling, phone normalization, etc.)
• campaignSender.ts — A function that sends a message to a list of phone numbers (representing a segment), using the send function above
• README.md — Documentation covering: the compliance approach taken (delivery timing restrictions, throughput management), and any infrastructure or registration requirements that must be completed before the system can go live

The implementation should use mock objects for the database (db) and queue (smsQueue) — no real connections are needed.