Case Study: ZweiDigital with Herzlack achieved 37% ROAS increase and 20% CPA reduction with Stape

ZweiDigital, a partner of Stape, enhanced online performance marketing for a growing German e-commerce brand Herzlack. They optimized Meta's CAPI setup by addressing tracking discrepancies and integrating Stape with Google Tag Manager. The result? A 37% increase in ROAS and a 20% reduction in CPA.

Herzlack’s growth strategy: leveraging online performance marketing

Herzlack is a fast-growing nail polish brand based in Germany. With a focus on handmade products and achieving the highest quality standards in production, they can satisfy their customers. 

Since the brand is not yet represented in large retail chains, its growth depends entirely on online marketing. Due to the high competition in Google, the company is forced to focus on generating demand, and the leading platform for this is Meta, which effectively helps to find and attract the target audience. As a lifestyle brand, Herzlack uses Instagram as an ideal medium for presenting its products. 

Campaign success largely depends on accurate data tracking, which allows Meta to transmit the correct signals and helps the algorithm determine the optimal target groups.  

Tracking challenges with Shopify’s Facebook sales channel

Herzlack is a Shopify shop, so it comes naturally to use the Shopify Facebook sales channel to integrate Meta tracking, including Conversions API (CAPI), to set up server-side tracking. Unfortunately, this is not working properly for all shops. Even though everything looks right in the Events Manager, there can be huge discrepancies when comparing the purchases tracked server-side with the actual sales in Shopify backends. Even when considering a decline in consent, numbers might be way off. 

ZweigDigital checks with every new client to see if this problem might affect them, and if so, the сompany decided to implement Meta Pixel and CAPI manually. In the case of Herzlack, an estimated 20% of sales was not tracked.

Why Stape is the Best Solution for CAPI Implementation

Whenever issues arise with CAPI tracking via plugins, Shopify, or other shop systems, the recommended solution is implementation via Stape, with the entire setup handled for the client.

Besides solving issues with missing sales and data, there are many reasons why ZweiDigital does not recommend opting for the seemingly easiest solution – a plugin. With the Stape setup, their clients receive significantly more data since Google Tag Manager (GTM), the foundation of the setup, can be hosted on their own domain using Stape Custom Loader. This makes it invisible to ad blockers and bypasses browser restrictions on third-party tracking, which impact GTM and all tracking within it. As a result, the accuracy of server-side tracking via Meta CAPI is greatly improved.

Individual Consent is, of course, respected, but it is a way around the browser already making a decision for the customer before he can opt in or -out on a website.

Integrating Stape with Shopify app for accurate tracking

ZweiDigital integrated the Google Tag Manager with the Stape Shopify app and set up Meta CAPI inside the GTM.

Stape has its own app for Shopify, an important factor in working with Shopify shops. Since Shopify introduced customer events, tracking anything in the checkout process has been hard, but Stape fits seemingly in the Shopify environment, respecting all aspects of customer privacy.

Stape Shopify App generates its own data layer, which is used to set up events in Google Tag Manager. With just a few infos from your Stape account, you can set up the app in minutes and profit from the stape custom loader and other benefits, like the cookie keeper, which prolongs cookie lifetime. This is especially important for customers with a longer sales cycle.

Information about previous ZweiDigital's experience with server Google Tag Manager container hosted by Stape is in the article Case Study:  ZweiDigital with SportSpare got 24% Cost-per-Purchase reduction and 32% Improvement of ROAS.

The impact: increased ROAS, lower CPA, and higher Event Match Quality

The great results achieved enabled an increase in the Meta ad budget to seven times the previous daily spending in the month following the implementation. 

With the CAPI manually set up with Stape, it became possible to: 

• increase ROAS by 37%; 
• decrease CPA by 20%; 
• improve Event Match quality by 10%. 

These measurable improvements directly enhanced the effectiveness of Meta Ads, leading to more Shopify sales.

Accurate tracking is a key success factor in maintaining strong client relationships. Since the pricing model is not based on the client's ad spend, there is no direct benefit from increasing the budget. The primary goal is to ensure the client's business succeeds and scales profitably. Reliable data is essential, and significant improvements are consistently seen when integrating CAPI via Stape. For this reason, educating clients on the benefits and providing full support with tracking setup remains a priority.

Why ZweiDigital recommends Stape for reliable server-side tracking

Continuous improvements in tracking are essential, and Stape consistently introduces new features while simplifying the setup process. As the go-to solution for CAPI integration, it offers a more reliable alternative to plugins or browser-based setups. While the initial setup requires more effort than installing a plugin, the long-term benefits outweigh this. Once configured, it runs smoothly without the need for ongoing maintenance.