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What is Subscriber Growth Rate (Email/SMS)?
Subscriber growth rate measures the pace at which your email or SMS marketing list grows over time. It reflects your ability to attract and retain engaged marketing contacts.
Why Subscriber Growth Rate matters?
Email and SMS remain high-ROI marketing channels for ecommerce, often outperforming paid ads in conversion rate and profitability. A healthy subscriber growth rate ensures a steady flow of new prospects and customers into your owned marketing ecosystem, reducing reliance on paid acquisition.
How Subscriber Growth Rate works?
Subscriber Growth Rate = ((New Subscribers − Unsubscribes) ÷ Starting Subscriber Count) × 100% over a chosen period. Tracking both gross and net growth is important, as aggressive list building can backfire if unsubscribes rise. Segmenting by source (pop-up forms, checkout opt-ins, social campaigns) can help identify the most effective list-building tactics.
Example in ecommerce
A fashion retailer adds a “10% Off First Order” pop-up on their site and promotes an SMS club on Instagram. Monthly subscriber growth rate jumps from 3% to 8%, and first-purchase conversion from these new subscribers hits 12%.
Common mix-ups
Subscriber growth rate is not the same as total list size. A large list can still have poor growth if unsubscribes and attrition outpace new sign-ups.
Best practices
- Use compelling incentives like discounts or early access.
- Optimize sign-up forms for mobile.
- Test different pop-up timing and triggers.
- Cross-promote sign-ups on social channels.
- Segment new subscribers for personalized onboarding.
- Monitor unsubscribe rate alongside growth to ensure list health.
- Keep opt-in processes simple and fast.
Industry benchmarks
- Healthy lists grow at 3-8% monthly, depending on acquisition efforts.
- Aggressive campaigns can push growth into double digits temporarily.
Related terms
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