Case study: How to Act Faster with Google Tag Manager

Client overview

Ską is one of the biggest price comparison engines in Poland. The site has been already on the Polish market for 11 years. Ską gives over 6 mln offers from majority of Polish e-commerce sites and it is viewed monthly by over 4 mln unique users.


Since the deployment every line of code was implemented by IT Department, it took weeks to deploy marketing codes. Due to this running simple questionnaire or tracking a new button became a reason for a new ticket which was postponing for weeks.

That was a big challenge because in a fast developing site maintenance of high quality tracking is crucial. New tracking codes deployment was engaging IT Department and waiting for crucial data was destroying Marketing Department performance. Data that was expected to take good decision flew too long to respond on markets expectations quickly.

That is why improving tracking codes deployment process became a project of the highest priority. Goal was simple–get relief for IT Department and enrich Marketing Department with crucial data on site usage and marketing channels performance.

Good mapping=the key to success

In order to reach the main goal of the project, we began with the verification of the current analytics and data processes. First of all we mapped all Google Analytics accounts and web properties where data was gathered.
It was really a great number of accounts! What is more we mapped all the advanced tracking that was so far deployed and hard coded on the website.

The only way to sustain a high level of digital analytics is to assure its fast development. That is why we also predicted what tracking could be needed in the future. It was very important in order to create full data layer which will assure scalability of the tracking in the future.

On the basis of the business analysis we prepared
a complete implementation plan. It covered not only current tracking but also foresee development of new tracking scripts.

Advanced Google Analytics implementation

Due to the fact that Skąpiec already had very advanced Google Analytics configuration we had to take an effort to move the implementation to Google Tag Manager without big dataLayer(.push) deployment. Actually they had almost all types of advanced tracking that can be deployed in a code of the website.

Data layer specification

Because of the fact that not all tags could cover current tracking we had to prepare dataLayer and dataLayer.push specification. This is very crucial element of the implementation because existence of well prepared dataLayer assures that business is IT-independent for a long time.

Of course, where it was possible we used Custom HTML tags with jQuery selectors in order
to inject dataLayer.push variables and theirs values via Google Tag Manager. Thanks to that we minimized engagement of the IT Department while Google Tag Manager implementation.

A/B testing

A moment of truth–deployment

In order to be double sure about the new implementation we installed parallel tracking. We used brand new Google Analytics account via Google Tag Manager. Next to it there stayed also current, hard coded tracking. After data comparison we decided to move the tracking to the „longest history” account and live it only serving via Google Tag Manager.

After the audit we began codes migration. In the process were engaged: Conversions’s consultants and IT Department. At the same time IT was switching off hard coded tracking (Skąpiec) and turning on tags in Google Tag Manager (Conversion). All the time we checked out everything in real-time reports in Google Analytics.

To be sure that the migration went well we compared transactions data between GA and CRM systems. What is more we also looked at server log data and compared it with page views from Behaviour > All pages reports in Google Analytics.

Everything worked great! Data was complete!


The tool itself does not improve a company’s performance. The most important are people who are able to use it.

That is why after the implementations we conducted the workshop where analysts and marketers were practicing Google Tag Manager.

After few days since the implementations, Skąpiec’s team implemented a new tracking with little help of Conversion. i took only one day since they got inquiry form the Marketing Department. Few weeks before it would have taken over week!


The project of Google Tag implementation and Google Analytics migrations took 6 weeks. We implemented over 100 tags, over 90 macros (variables) and 30 rules (triggers). Beside Google Analytics we migrated also numbers of scripts like Gemius Audience, remarketing codes and qualitative tools like Qualaroo.

Was it worth it?

This was really challenging project. It is sure that the effort was worth all the outcomes that Skąpiec got:
Google Tag Manager implementation gave measurable savings in IT Department’s time consumption. What is more other departments became more efficient–eg. Marketing Department does not have wait for codes implementation for weeks.

Website——works faster because all scripts are loaded asynchronically.

Google Tag Manager implementation opened doors for Analytics Department and gave new ways (data) of analysis.

If you need an audit of your current analytics tool (Google Analytics, AT Internet, Adobe Analytics or Webtrends) or you would like to set up a comprehensive data quality assurance process, contact Mavenec today to learn more about our approach to ensuring data quality. You can also learn more about digital analytics by downloading our Ultimate Conversion Rate Optimization Toolkit.

Author: Mariusz Michalczuk

I am a co-founder of Mavenec. For over 5 years I have been focused on creating business value by leveraging data from digital channels. With strong statistical background and certifications from top analytics vendors I change business leaders’ approach to digital marketing from gut- to data-driven.

Follow me on Twitter: @mariuszmich


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