Addingwell is a fully-managed GTM server-side hosting + tooling (monitoring, adblocker bypass, Safari resilience) to improve data quality, performance and governance.

Retention.com's identity resolution software helps Shopify merchants recover lost shoppers and increase Klaviyo flow revenue.
| Feature | Addingwell | Retention.com | Littledata |
|---|---|---|---|
| Works with platforms other than Shopify | ✔️ | ✔️ | |
| Identity resolution to boost audiences | ✔️ | ✔️ | |
| Customer data to marketing platforms | ✔️ | ✔️ | |
| 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 | ✔️ |
Addingwell focuses on server-side GTM hosting to improve tracking accuracy, ad blocker bypass, and Safari resilience — useful for tag management and performance, but it still relies on GTM's browser-side layer, limiting its ability to capture server-level Shopify events or enrich data with customer context.
Retention.com specializes in identity resolution to recover anonymous shoppers and feed audiences into platforms like Klaviyo — strong for email retargeting, but not a full tracking/data collection solution.
Neither is Littledata. Since neither offers Direct from Shopify's servers, both miss server-native event capture — meaning checkout steps, post-purchase flows, and customer-enriched data that the browser never sees can go untracked.
Littledata wins by pulling data directly from Shopify's servers with no-code setup, automatic checkout tracking, native Shopify Markets support, identity resolution, and a 30-day free trial — giving you the most complete, accurate customer journey data with minimal overhead.
Addingwell vs Retention.com's customer reviews
| Addingwell | Retention.com | 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 | The support was very fast to answer our questions and super helpful. Just be careful to check that the events don't trigger twice. | "Unfortunately, the team... very high employee turnover; it can be really frustrating to have to re-explain things to new reps." | "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 |
Addingwell vs Retention.com's monthly subscription cost
| Store size | Addingwell | Retention.com | Littledata |
|---|---|---|---|
| 50 orders / month | $90 | $500 | $39 |
| 500 orders / month | $90 | $500 | $175 |
| 5,000 orders / month | $130 | $2000 | $540 |
| 20,000 orders / month | $400 | $5000 | $1390 |
Sources: Addingwell pricing, Littledata pricing. Prices last verified July 10, 2026.
For an online store with 50 orders per month, Addingwell is 82% cheaper than Retention.com and 77% cheaper than Littledata. At 500 orders, Addingwell and Retention.com are equal, while Littledata is 94% more expensive. For 5000 orders, Addingwell is 93% cheaper than Retention.com and 76% cheaper than Littledata. At 20,000 orders, Addingwell is 92% cheaper than Retention.com and 69% cheaper than Littledata. Retention.com incurs additional implementation costs for higher order volumes.
| Destination | Addingwell | Retention.com | Littledata |
|---|---|---|---|
| Google Analytics | ✔️ | ✔️ | |
| Meta Ads | ✔️ | ✔️ | |
| TikTok | ✔️ | ✔️ | |
| Google Ads | ✔️ | ✔️ | |
| ✔️ | ✔️ | ||
| Microsoft Ads | ✔️ | ✔️ | |
| Klaviyo | ✔️ | ✔️ | |
| Snap | ✔️ | ||
| Segment | ✔️ | ||
| Attentive | ✔️ |
Addingwell focuses on ad platform tracking (paid media optimization via server-side events), improving signal quality for bidding algorithms across major ad networks.
Retention.com specializes in identity resolution + email/SMS retargeting, sending enriched visitor data exclusively to Klaviyo to recover anonymous traffic through owned channels.
Littledata offers the broadest hybrid coverage, combining ad platform destinations (like Addingwell) plus owned marketing tools (Klaviyo, Attentive) plus Segment for data warehousing — making it the most versatile stack for brands wanting both paid media accuracy and owned channel enrichment in one solution.
Bottom line: Addingwell = paid ads. Retention.com = Klaviyo identity resolution. Littledata = both, plus data infrastructure.

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.