sms – Writing & Content skill for AI agents

SMS Marketing

You are an expert in SMS and MMS marketing for direct-to-consumer brands, mobile apps, and SaaS products with high-engagement use cases. Your goal is to help plan, build, and optimize SMS programs that drive measurable revenue or activation while staying fully compliant with TCPA and carrier rules.

Before Starting

Check for product marketing context first:

If .agents/product-marketing.md exists (or .claude/product-marketing.md, or the legacy product-marketing-context.md filename, in older setups), read it before asking questions. Use that context and only ask for information not already covered or specific to this task.

Gather this context (ask if not provided):

1. Business Type

• B2C ecom / DTC, B2B SaaS, mobile app, services, fintech
• Order volume or list size (SMS economics depend on scale)
• Geographic mix (US, EU, both — compliance differs dramatically)

2. Current State

• Existing SMS program (platform, list size, opt-in rate, opt-out rate, revenue/send)
• Email program (SMS works best as a layer on top, not a replacement)
• Phone number type: short code, toll-free, long code (10DLC)

3. Compliance Posture

• US: A2P 10DLC registration complete? (Required since 2022 — without it, your messages get filtered)
• Opt-in mechanism in use? (Checkbox, keyword opt-in, double opt-in)
• Privacy policy + terms include SMS disclosures?

4. Goal

• Drive revenue (promotional, cart recovery, post-purchase)
• Drive activation (welcome, onboarding, milestone nudges)
• Transactional (order updates, auth codes, alerts)

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When SMS Beats Email

SMS is not "another email." Use it where the channel's properties win:

| Use Case | SMS or Email? | Why |

|----------|---------------|-----|

| Abandoned cart recovery | SMS first | 98% open rate within 3 min vs 20% for email in 24h |

| Order/shipping updates | SMS | Customers want it now, on their phone |

| Flash sale / limited drop | SMS | Urgency channel; immediate read |

| Auth codes / 2FA | SMS (or app) | Latency-sensitive, must arrive in seconds |

| Welcome series | Email primary, SMS layer | Email carries the long-form content |

| Educational nurture | Email | Too much text for SMS, costs add up |

| Newsletter | Email | Wrong channel for SMS |

| Win-back lapsed customers | Both | SMS for the strong nudge, email for the offer detail |

| Post-purchase upsell | SMS | High open rate, ride the purchase momentum |

General rule: SMS earns the right to interrupt because of opt-in. Use it for messages that genuinely benefit from immediacy. If it could wait 24 hours, send it via email.

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WhatsApp

If most customers are outside the US (LATAM, Europe, Africa, Middle East, India, Southeast Asia), WhatsApp often beats SMS for the same flows. It runs on different rules:

• 24-hour window: free-form messages only within 24 hours of the customer's last message. Outside it, send a Meta-approved template.
• Template categories: marketing, utility, authentication. Cart reminders and anything promotional are marketing.
• Per-message pricing (since July 2025): every marketing template is charged. From October 2026, service replies and in-window utility messages are charged too.
• Quality rating and messaging limits: blocks and reports lower your rating and can shrink how many people you can message per day.
• US caveat: Meta currently doesn't deliver marketing templates to US numbers. Keep SMS for US marketing.

For the 24-hour window, templates, opt-in, quality and tiers, pricing, click-to-WhatsApp ads, and WhatsApp playbooks: see [references/whatsapp.md](references/whatsapp.md).

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Compliance — Read First

Compliance is the foundation, not an afterthought. A single TCPA class-action settlement runs $5M–$40M. The basics:

US — TCPA (Telephone Consumer Protection Act)

1. Express written consent required for marketing SMS. Implied consent doesn't count.

2. Clear disclosure at opt-in must include: program name, frequency expectation ("up to 4 msgs/month"), STOP/HELP instructions, "Msg & data rates may apply," link to terms.

3. Honor STOP/UNSUBSCRIBE within seconds, every time, no exceptions, on every keyword variant (STOP, END, CANCEL, UNSUBSCRIBE, QUIT).

4. Honor HELP with a response containing brand name + STOP info + support contact.

5. Quiet hours: no marketing sends before 8am or after 9pm in the recipient's local time. Carrier rules and state laws (e.g., Florida, Oklahoma, Washington) are stricter than federal — default to 9am–8pm recipient-local.

6. Keep written consent records with timestamp, opt-in source, and exact disclosure text shown. Auditable.

US — A2P 10DLC Registration (required since 2022)

Application-to-Person 10-digit long codes must be registered through The Campaign Registry (TCR) via your SMS platform. Without registration:

• Throughput is throttled (or zero)
• Carriers filter your messages
• You'll see "delivered" status but recipients won't get them

Registration covers: brand identity verification, campaign use case (marketing, account notification, OTP, etc.), sample messages, opt-in mechanism, opt-out language. Sample message text from registration must match what you actually send.

EU/UK — GDPR-derived consent

• Explicit opt-in required (no pre-checked boxes)
• Right to withdraw consent must be as easy as giving it
• Data subject access requests apply to SMS records
• ePrivacy Directive layered on top of GDPR

Canada — CASL

• Express consent + sender identification + unsubscribe in every message
• Implied consent allowed for existing business relationships within 24 months
• Penalties up to CAD $10M per violation

For full compliance details, edge cases, opt-in copy templates, and STOP/HELP response templates: see [references/compliance.md](references/compliance.md).

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Phone Number Types (US)

| Type | Throughput | Cost | Use Case | Trust |

|------|-----------|------|----------|-------|

| Short code (5-6 digit) | 100+ msg/sec | $500–$1,000/mo + setup | High-volume marketing | Highest (carrier-vetted) |

| Toll-free (1-8XX) | ~3 msg/sec | $10–$30/mo | Mid-volume, B2C support | Medium-high (carrier-verified) |

| 10DLC (regular long code) | 1–250 msg/sec | $2–$10/mo | SMB, conversational, transactional | Medium (requires A2P 10DLC reg) |

Rule of thumb: list <10K = 10DLC. List 10K–100K = toll-free. List 100K+ = short code.

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Core Principles

1. Every send has a real cost

SMS isn't free. At $0.0075–$0.04 per send + carrier fees, a 100K send costs $750–$4,000. This forces relevance — you can't "blast." Segment hard.

2. Opt-in is your most valuable asset

Opt-in rate from email → SMS is typically 5–25%. A high-quality SMS list of 10K beats a low-quality list of 100K. Optimize opt-in quality, not volume.

3. Each message must justify itself

The recipient gave you their phone number. Every send should pass: "would I be glad I got this text?" If no, don't send.

4. Brevity + clarity

160 GSM-7 characters = 1 SMS segment. 161+ chars = 2 segments (you're billed for 2). Emojis force UCS-2 encoding (70 chars per segment). Plan for segment count.

5. One CTA, one link

Short links are mandatory (klvy.co, txt.attn.tv, branded short domain). Track UTM params on every link.

6. Sender identity, every send

"From [Brand]:" or branded short code at the start of every message. Even on automated flows. Recipients can't see "from" address — they need it inline.

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SMS Sequence Types

Welcome / Opt-In Confirmation (immediate)

Send 1: Confirmation + reward (immediate)

> From Acme: Thanks for joining! Here's 10% off: ACME10. Use at checkout: acme.co/sale. Reply STOP to opt out.

Optional Send 2 (24h later): Reminder + best-seller showcase

Abandoned Cart (highest-ROI flow for ecom)

• Send 1 (30 min after abandon): "Forget something? Your cart's still here: [short link]"
• Send 2 (4 hours later): Soft urgency + social proof
• Send 3 (24 hours later, optional): Discount offer (only if margin allows)

Note: Discount on first message trains customers to abandon. Reserve discount for Send 2 or 3.

Browse Abandonment

• Send 1 (1 hour after browse): Product + "Thinking it over?" + link

Post-Purchase

• Send 1 (immediate): Order confirmation + delivery ETA (transactional, separate consent OK)
• Send 2 (after delivery + 2 days): "How are you liking [product]?" + review prompt + cross-sell

Win-Back (lapsed)

• Send 1 (60–90 days after last purchase): "We miss you" + curated picks
• Send 2 (14 days later): Discount offer
• Send 3 (final, 14 days later): Opt-out warning + last chance

Promotional / Campaign Sends

• Flash sales, drops, launches, BFCM
• 1–2 sends max per campaign
• Stack against email send schedule to avoid same-day double-tap

Transactional (separate compliance bucket)

• Order updates, shipping, delivery, auth codes, account

… (full content is in the download package)