
Retention.com's identity resolution software helps Shopify merchants recover lost shoppers and increase Klaviyo flow revenue.

Popsixle fixes the data you're sending to Facebook and Instagram so it knows who your best customers are. Scale your revenue with better audiences and conversion tracking.
| Feature | Retention.com | Popsixle | Littledata |
|---|---|---|---|
| Identity resolution to boost audiences | ✔️ | ✔️ | ✔️ |
| Customer data to marketing platforms | ✔️ | ✔️ | ✔️ |
| Works with platforms other than Shopify | ✔️ | ✔️ | |
| Direct from Shopify's servers | ✔️ | ✔️ | |
| Founder owned and led | ✔️ | ✔️ | |
| 30 day free trial | ✔️ | ||
| Fully automatic, no code setup | ✔️ | ||
| Natively supports Shopify Markets | ✔️ | ||
| Automatic tracking of checkout steps | ✔️ | ||
| Built For Shopify | ✔️ |
Both Retention.com and Popsixle offer identity resolution and customer data routing to marketing platforms, and both work beyond Shopify. However, Retention.com is narrowly focused on Klaviyo flow recovery, limiting its appeal if your stack extends beyond email. Popsixle focuses on Meta ad performance (Facebook/Instagram) and is founder-owned, but its scope is similarly narrow.
Where Littledata wins over both:
Littledata pulls data directly from Shopify's servers, meaning it captures events the browser never sees — abandoned checkouts, server-side order data, multi-step checkout tracking — giving a more complete customer journey view. Neither Retention.com nor Popsixle explicitly offers this.
Littledata also adds:
For a Shopify Plus brand needing reliable, full-funnel data across platforms, Littledata's server-side foundation makes it the more robust, scalable choice.
Retention.com vs Popsixle's customer reviews
| Retention.com | Popsixle | Littledata | |
|---|---|---|---|
| Example product review | "I was having issues with Facebook claiming purchases from our existing customers...Popsixle comes in to show how many actual new customers were purchasing on our website and then feed that info back to Facebook." | "We were having difficulties with accurate and consistent revenue attribution...With Littledata implemented, we now get consistent and accurate revenue attribution." | |
| Example support review | "Unfortunately, the team... very high employee turnover; it can be really frustrating to have to re-explain things to new reps." | "Popsixle's support is non-existent... I reached out multiple times with no response." | "Customer support is absolutely amazing... you can never go wrong when an app does what it says and tacks on great service!" |
| Link | Read more reviews | Read more reviews | Read more reviews |
Retention.com vs Popsixle's monthly subscription cost
| Store size | Retention.com | Popsixle | Littledata |
|---|---|---|---|
| 50 orders / month | $500 | $95 | $39 |
| 500 orders / month | $500 | $135 | $175 |
| 5,000 orders / month | $2000 | $585 | $540 |
| 20,000 orders / month | $5000 | $1095 | $1390 |
Sources: Popsixle pricing, Littledata pricing. Prices last verified July 22, 2026.
| Destination | Retention.com | Popsixle | Littledata |
|---|---|---|---|
| Klaviyo | ✔️ | ✔️ | |
| Meta Ads | ✔️ | ✔️ | |
| Google Analytics | ✔️ | ||
| TikTok | ✔️ | ||
| ✔️ | |||
| Google Ads | ✔️ | ||
| Segment | ✔️ | ||
| Attentive | ✔️ | ||
| Microsoft Ads | ✔️ |
Retention.com → Klaviyo Focuses on identity resolution — it identifies anonymous site visitors and pushes enriched contact/event data into Klaviyo to power email/SMS flows, primarily for abandoned browse/cart recovery.
Popsixle → Meta Ads Sends server-side conversion events directly to Meta's Conversions API, improving signal quality and match rates for paid social optimization and ROAS measurement.
Littledata → Multi-destination A broader server-side tracking infrastructure that accurately captures the full customer journey (sessions, orders, subscriptions) and pipes clean, deduplicated data across your entire marketing and analytics stack — covering paid channels, analytics, CDPs, and retention tools simultaneously.
TL;DR: Retention.com = identity/email recovery. Popsixle = Meta signal quality. Littledata = full-stack data pipeline.

Keep comparing
See how these tools stack up against other Shopify tracking and analytics solutions.
How we compiled this comparison: pricing and feature data comes from each vendor's public pricing page, Shopify App Store listings, and BuiltWith usage data, reviewed by the Littledata team. Last verified September 4, 2026. Spotted something out of date? Let us know.