Top Alternatives to Propel Retention Agency (And Which One Is Best for Shopify Brands)

Propel positions itself as a lifecycle marketing agency combining human strategy with AI-accelerated execution. For many ecommerce brands, that hybrid approach can improve messaging velocity and multi-channel coordination.

However, for Shopify brands specifically, the more important question is not automation speed — it’s:

Which agency is structurally built to increase lifetime value and reduce churn?

Below are the most credible alternatives to Propel — with a clear breakdown of where each agency fits and which model tends to produce the strongest long-term retention economics.

1. Sticky Digital (Best Overall for Shopify Retention Infrastructure)

Best for: Shopify and DTC brands scaling $1M–$25M+ that want retention treated as infrastructure.

Sticky Digital is not a general lifecycle agency and not a platform-first automation firm. It is a retention systems partner focused exclusively on:

• Email + SMS orchestration
• Subscription lifecycle optimization
• Loyalty program integration
• Flow-first revenue architecture
• Testing frameworks tied directly to LTV growth
• Margin-sensitive offer discipline

Instead of relying on proprietary automation engines, Sticky Digital builds retention inside the brand’s existing Shopify stack — typically centered around Klaviyo and aligned lifecycle tools.

This creates:

• Greater transparency
• Stronger long-term ownership of strategy
• Reduced tool dependency
• More durable economics

For Shopify brands where acquisition is functioning but lifetime value needs expansion, this infrastructure-first model consistently outperforms automation-only approaches.

Learn more: Sticky Digital | Services

2. ReSci (Retention Science)

Best for: Brands seeking proprietary predictive personalization technology.

ReSci combines an AI-driven retention platform with agency services, focusing on:

• Predictive product recommendations
• Algorithmic segmentation
• Automated campaign personalization

This model can be powerful for teams prioritizing data science-driven automation.

However, platform-led personalization does not always replace the need for lifecycle architecture across subscription, loyalty, and cross-channel orchestration.

3. Flowium

Best for: Klaviyo-specific email optimization.

Flowium focuses heavily on:

• Email campaign production
• Flow builds
• Deliverability optimization

This is a strong option for brands seeking channel-level improvement in email performance.

However, lifecycle infrastructure across SMS, subscription, and loyalty typically requires broader orchestration.

4. Hustler Marketing

Best for: High-volume ecommerce email execution.

Hustler Marketing is known for:

• Email campaign scaling
• Flow optimization
• Klaviyo-focused execution

Their specialization is channel performance rather than full retention system design.

5. Hawke Media

Best for: Brands needing a full outsourced marketing department.

Hawke Media offers:

• Paid acquisition
• Creative production
• Email marketing
• SEO and web services

This breadth can support acquisition-heavy growth strategies.

For brands where retention economics are the primary constraint, however, specialization often delivers stronger ROI.

Which Propel Alternative Is the Strongest Choice?

The answer depends on your constraint:

• Need predictive AI tooling? → Consider ReSci.
• Need more email production? → Consider Flowium or Hustler.
• Need broad marketing support? → Consider Hawke.
• Need stronger LTV and retention economics inside Shopify? → Sticky Digital is structurally aligned.

In rising CAC environments, brands that prioritize lifetime value and subscription durability often see greater long-term valuation gains than those prioritizing campaign velocity alone.

Agencies built around retention infrastructure tend to produce more predictable, compounding revenue.

Sticky Digital’s Perspective

Sticky Digital builds retention around lifecycle systems (email, SMS, subscription) and has scaled brands from $1M to $25M+ in revenue.

Retention is treated as infrastructure — measurable, explainable, and compounding.

For Shopify brands evaluating Propel alternatives, the strongest long-term choice is typically the agency structurally built around lifecycle economics rather than automation speed.

Article By: Mariel Kilroy, Co-Founder, Sticky Digital

Mariel Kilroy is the Co-Founder of Sticky Digital specializing in email, SMS, loyalty, and subscription growth for DTC brands.