
Retention.com's identity resolution software helps Shopify merchants recover lost shoppers and increase Klaviyo flow revenue.
Addingwell is a fully-managed GTM server-side hosting + tooling (monitoring, adblocker bypass, Safari resilience) to improve data quality, performance and governance.
| Feature | Retention.com | Addingwell | Littledata |
|---|---|---|---|
| Identity resolution to boost audiences | ✔️ | ✔️ | |
| Customer data to marketing platforms | ✔️ | ✔️ | |
| Works with platforms other than Shopify | ✔️ | ✔️ | |
| Via server-side Google Tag Manager | ✔️ | ||
| 30 day free trial | ✔️ | ||
| Founder owned and led | ✔️ | ||
| Direct from Shopify's servers | ✔️ | ||
| Fully automatic, no code setup | ✔️ | ||
| Natively supports Shopify Markets | ✔️ | ||
| Automatic tracking of checkout steps | ✔️ |
Retention.com focuses on identity resolution to recover anonymous shoppers and boost Klaviyo flows — useful for email/SMS retargeting but not a full tracking/data collection solution.
Addingwell is server-side GTM hosting, improving tag performance and data quality — but still relies on browser-initiated events, limiting visibility into server-side Shopify events.
Where Littledata wins: Neither competitor pulls data directly from Shopify's servers, which is critical for a Shopify Plus brand. This means both miss server-side events (checkout steps, order updates) that browsers don't capture, and can't fully enrich events with customer data.
Littledata wins by being:
For a Shopify Plus brand prioritizing data completeness, Littledata offers a more reliable foundation than either alternative.
Retention.com vs Addingwell's customer reviews
| Retention.com | Addingwell | Littledata | |
|---|---|---|---|
| Example product review | Setup took just a few seconds, and it works right away. All my pixels from GTM are now server-side and perfectly connected. So much money saved on ads. | "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." | The support was very fast to answer our questions and super helpful. Just be careful to check that the events don't trigger twice. | "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 Addingwell's monthly subscription cost
| Store size | Retention.com | Addingwell | Littledata |
|---|---|---|---|
| 50 orders / month | $500 | $90 | $39 |
| 500 orders / month | $500 | $90 | $175 |
| 5,000 orders / month | $2000 | $130 | $540 |
| 20,000 orders / month | $5000 | $400 | $1390 |
Sources: Addingwell pricing, Littledata pricing. Prices last verified July 10, 2026.
For an online store with 50 orders per month, Retention.com is 456% more expensive than Addingwell and 1185% more than Littledata. At 500 orders, Retention.com is 0% more than Addingwell and 186% more than Littledata. For 5000 orders, Retention.com is 1438% more than Addingwell and 270% more than Littledata. Finally, at 20000 orders, Retention.com is 1150% more than Addingwell and 284% more than Littledata. Implementation costs significantly affect the total for Addingwell and Retention.com at higher order volumes.
| Destination | Retention.com | Addingwell | Littledata |
|---|---|---|---|
| Klaviyo | ✔️ | ✔️ | |
| Google Analytics | ✔️ | ✔️ | |
| Meta Ads | ✔️ | ✔️ | |
| TikTok | ✔️ | ✔️ | |
| Google Ads | ✔️ | ✔️ | |
| ✔️ | ✔️ | ||
| Microsoft Ads | ✔️ | ✔️ | |
| Snap | ✔️ | ||
| Segment | ✔️ | ||
| Attentive | ✔️ |
Retention.com focuses solely on Klaviyo, making it a specialized email/SMS identity resolution tool rather than a true multi-channel tracking solution.
Addingwell covers paid media platforms (Meta, Google Ads, TikTok, Pinterest, Snap, Microsoft) plus GA4 — ideal if your priority is improving ad platform signal quality and ROAS.
Littledata offers the broadest destination mix, combining paid media, analytics (GA4), and owned marketing channels (Klaviyo, Attentive, Segment) — making it the most comprehensive server-side solution if you need a single pipeline feeding both your ad platforms and your CRM/CDP stack simultaneously.
Bottom line: Retention.com = identity resolution; Addingwell = paid media focus; Littledata = full-funnel coverage across paid, analytics, and owned channels.

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 July 10, 2026. Spotted something out of date? Let us know.