All three offer identity resolution and audience enrichment for marketing platforms. Aimerce adds no-code setup and pulls data directly from Shopify's servers, but lacks Retention.com's cross-platform flexibility. Retention.com focuses narrowly on recovering lost shoppers and boosting Klaviyo flows, but doesn't pull directly from Shopify's servers, limiting its ability to enrich events with customer data or track server-side events the browser misses.

Littledata wins on completeness: it combines server-side data direct from Shopify (like Aimerce) with a 30-day free trial, native Shopify Markets support, and automatic checkout step tracking — features neither competitor offers. Unlike Retention.com, Littledata isn't browser-dependent, so it captures the full customer journey. Unlike Aimerce, it's not founder-stage — it's a mature, proven solution. For a Shopify Plus brand needing reliable, scalable, full-funnel data with minimal setup, Littledata is the strongest choice.

For an online store with 50 orders, Aimerce is 40% cheaper than Retention.com and 87% more expensive than Littledata. At 500 orders, Aimerce and Retention.com are equal, while Littledata is 50% cheaper than both. With 5,000 orders, Aimerce is 75% cheaper than Retention.com and 43% more expensive than Littledata. At 20,000 orders, Aimerce is 64% cheaper than Retention.com and 125% more expensive than Littledata. Overall, Littledata consistently offers the lowest pricing across all order volumes.

Aimerce focuses on ad platform activation + Klaviyo — useful for paid media optimization and email.

Retention.com is narrowly focused on Klaviyo only, positioning itself purely as an identity resolution/email revenue tool rather than a broad tracking solution.

Littledata offers the widest destination coverage — spanning analytics (GA4), major paid channels, affiliate/social platforms, CDPs (Segment), and SMS (Attentive) — making it the most versatile for a full-stack data infrastructure.

Key takeaway: If your priority is multi-channel ad tracking + analytics, Littledata wins on breadth. If you're laser-focused on Klaviyo revenue attribution, Retention.com is specialized. Aimerce sits in the middle, balancing paid media and email.