Grow your subscriber lists compliantly
A strategic approach to list growth is essential to any marketing plan, especially one focused on mobile. Mobile channels are more direct, so prospects are often hesitant to share their phone number or take the next step to download an app and enable push notifications. Getting someone to subscribe often means making it as easy as possible for someone to do so, right now, on their phones, and with few barriers that can lead to further hesitation.
Let’s run through some of the top ways to grow your mobile-specific marketing lists beyond general acquisition tactics.
It is important to have 1 main list for each distinct marketing channel to remain compliant and organized.
Custom keywords
You can create custom keywords for both text and WhatsApp to speed up list growth. When a person sends your subscribe keyword, they’re automatically added to your list and can start receiving messages right away.
Channels: Text and WhatsApp
Best practices:
- Choose relevant (on-brand), intuitive, and easy-to-spell keywords; meanwhile, avoid complex terms, abbreviations, or numbers.
- Create keywords that align with specific promotions (e.g., in-store holiday promotion, online contest entry, general 15% off, etc.). This allows you to not only get creative with custom keywords, but also segment new subscribers based on their point of entry and measure campaign effectiveness.
- Use your keyword to create robust click-to-text or click-to-WhatsApp ads on social media (learn more in the next tab!).
Tap-to-text
Tap-to-text is exactly what it sounds like: users will see an ad encouraging them to click a button to opt in for text message marketing. For WhatsApp, this is tap-to-WhatsApp. This method capitalizes on a user's immediate interest by providing a seamless opt-in pathway.
Channels: Text and WhatsApp
Best practices:
- Add a "click to text" link to your Instagram bio, which automatically opens the user's messaging experience (text or WhatsApp) with your phone number and a pre-written subscribe keyword.
- Offer a valuable incentive to subscribe (e.g., 15% off or entry into a giveaway) that encourages people to share their phone number.
- Promote via both Instagram stories and posts:
- Stories: Add the "Link" sticker to relevant Instagram Stories to drive traffic to your click-to-text URL.
- Posts/Reels: In the caption of posts and reels, include a strong CTA directing users to "Tap the link in our bio to text us and join the club!"
Note: With iOS26 in mind, tap-to-text should be a preferred opt-in method. This will help prevent your brand messages from being filtered into the “unknown” inbox.
Email buttons
Use email buttons to collect new mobile subscribers who have already consented to email.
Channels: Text, WhatsApp, App downloads
Best practices:
- Add a brief but clear reason to subscribe (e.g., "Be the first to know," "Get real-time tracking," or "Exclusive offers sent only via [channel]”.
- A/B test button designs, copy, and placement.
- Send to segments that are most likely to engage with a new channel (e.g., recent purchasers or highly engaged email subscribers).
- Place consent buttons above the fold or immediately following the primary email content to maximize visibility.
QR codes
QR codes bridge the gap between physical touchpoints (e.g., retail stores, product packaging, print ads, events) and the digital world. They eliminate manual entry errors and provide a friction-free path to opt-in.
Channels: Text, WhatsApp, App downloads
Best practices:
- Set your QR code to lead to your consent collection method (e.g., a full page sign-up form or click to text form for text message consent; your app to trigger an in-app pop-up for push; or WhatsApp with a pre-set welcome or opt-in message).
- Add a hidden field to your QR code forms to add a profile property to any new subscribers. You can use that information to understand your QR code’s success, adjust your welcome flow for these subscribers, and even tailor later communication.
- Add your QR code across in-store signage, at in-person checkout, via direct mail and catalogs, and in product packaging.
Note: There are many websites that can help you generate a QR code, such as Canva or Swapt.
Mobile-specific pop-ups
Create a pop-up dedicated specifically to growing your mobile subscriber lists. This can include both:
- Text or WhatsApp: Target those on-site who opted in to email but not a mobile channel.
- Push notifications: Target those in-app who have not yet enabled push, with app-specific forms.
Channels: Text, WhatsApp
Best practices:
- Offer exclusive value that someone cannot already get via email (e.g., early access, VIP perks, extra loyalty points).
- Ensure the pop-up sets expectations for your typical message frequency and content.
- Time the popup to appear when the user is most engaged, such as after viewing multiple pages in a row, spending a set amount of time on a particular page, or exit intent after reaching the checkout page (before completing a purchase).
Keep compliance in mind
You must obtain explicit consent from recipients before sending both marketing and transactional messages.
So, if you’re collecting phone numbers from subscribers, ensure your disclosure language includes any required compliance language (like message frequency and opt-out instructions, e.g., “Msg & data rates may apply. Reply STOP to opt out.”). Text messaging in particular comes with strict compliance regulations. Bookmark our documentation around text message compliance.
Your terms of service, privacy policy, and disclosure language should likewise be updated and reviewed by your legal team (or a legal representative) to comply with data privacy laws, protecting you and your customers as you broaden your mobile strategy.
Prioritize which list growth strategies to try first
By now, you’ve learned many ways to grow your list across channels, and now in this case, for mobile channels specifically.
If you’re feeling a bit overwhelmed, don’t panic! You don’t need to conquer all of these at once. Prioritize the best acquisition tactics for your team, your brand, and your customers.
Let’s run through 3 steps to pinpoint which list growth strategy you should try out next.
First and foremost: Which channel is your highest priority right now?
As a reminder, here’s how to prioritize each mobile channel based on their main strengths:
- Text: If you need broad reach and fast action.
- WhatsApp: If you have customers in WhatsApp heavy regions.
- Push: If you have an app and repeat customers.
Conduct a thorough analysis of existing customer habits and mobile behavior before investing in additional list-growth strategies. You can do so in Klaviyo and in external tools, such as your website provider or Google Analytics.
Why? Because you should invest in areas where your customers (or ideal future customers) show up most.
Next, determine your goal for list growth. Is it more about:
- Increased volume of signups (quantity): Choose lower-friction capture and broader placement across your site, app, or social presence.
- Enhanced quality of signups (quality): Choose higher-intent lead-capture opportunities, value-tied prompts, and stronger targeting to specific segments (or audiences on social).
Finally, consider where your customers are, most often, and at their most engaged.
If it’s on your website:
- Text: Set up a pop-up or embedded form on the PDP and cart.
- WhatsApp: Add a click to WhatsApp button on key pages.
- Push: Promote app install first, then push opt-in in-app.
If it’s in your app:
- Push: Add an in-app permission prompt tied to value (order updates, back-in-stock, drops)
- Text and WhatsApp: Push users to in-app preference center or account settings to opt-in
If retail or in-person presence matters:
- All channels: Prioritize QR codes at POS and packaging inserts
- Text and WhatsApp: Promote social links that land on a focused opt-in page