Case Sentinels


PureDigital and Sentinels started collaborating in September 2022, to improve Search Engine Advertising (SEA) results. During the collaboration, we worked closely with the Sentinels marketing department. Together we increased the number of conversions in just 3 months by 40%, while decreasing the cost per acquisition (CPA) by -16%. Curious how we did this? Read more in this case study.

Collaboration structure

Nowadays a lot of our customers also have in-depth online marketing knowledge in-house. This was also the case at Sentinels, where a marketing team of four dedicated professionals were running the SEA account. The need of those customers is more based on strategy than pure execution. That’s why, after the introduction call, we decided to start a collaboration, where PureDigital was responsible for the strategy and roadmap, and Sentinels did the execution of the tasks. We used Monday as a project management tool, Slack for direct communication, and a weekly video call via Google Meet. This ensured smooth communication, proper execution of tasks, and better SEA results.

About the Sentinels marketing team

The Sentinels marketing department was a cohesive unit composed of four dedicated professionals, each possessing distinct expertise. Together, they achieved an impressive 15x growth in the marketing pipeline within a year. Here’s an overview of the team’s structure and their specific roles:

Nikiforos Aslanoglou
Digital Marketing Manager: As the driving force behind the growth of Sentinels’ paid channels, Nikiforos was our key contact and a critical player in the team. Our joint work with him led to a marked enhancement in the paid search campaign outcomes. With his main KPI being the driving of pipeline growth for paid search, Nikiforos’s role extended beyond simple oversight. He was deeply involved in analyzing campaign results, generating insightful suggestions based on careful examination of the data. His responsibilities also included providing detailed weekly and monthly performance updates to both the marketing and commercial teams, thus maintaining transparency and alignment across various facets of the business. His multifaceted role was vital in shaping Sentinels’ overall marketing success.

Dhanum Nursigadoo
Senior Content Manager: Dhanum Nursigadoo, with his deep market expertise and skills in crafting high-conversion copy, was instrumental in our campaigns. In close collaboration with Nikiforos, Dhanum’s focus was to elevate CTAs by fine-tuning campaign headlines, optimizing descriptions, and generating compelling ebooks.

Maria Sembodo
Marketing Automation Manager: Maria looked after Sentinels’ CRM and email marketing initiatives. Her role was pivotal in handing over qualified leads to sales and powering our remarketing campaigns with lead lists featuring those who interacted with Sentinels’ content across several platforms.

Andre Stoorvogel
Hoofd Marketing: Andre guided the team in pursuit of Sentinels’ growth targets. Our partnership with Andre involved determining annual and quarterly KPIs and analyzing campaign outcomes.

In summary, every individual in Sentinels’ marketing team played an essential part in driving the company’s growth, marking the success of our collaboration.

Optimization roadmap

In the first 3 months of the collaboration we worked on the following topics:

September – fixing the basics: from creating a conversion set, adding missing ad extensions, and prioritizing conversions with fictive values, to adjusting the campaign settings.

Oktober – zoekwoordonderzoek en meer: from doing extensive keyword research, changing bid strategies to Target ROAS, to optimizing responsive search ads.

November – nieuwe accountstructuur: from adjusting the campaign structure to 1 campaign per objective, adding a remarketing layer, to a structural process for search term optimization.

Due to the effective collaboration process, we were able to optimize the SEA account effectively in terms of consultancy hours. Which is besides the results always a KPI for our collaboration.


The main objective of the SEA collaboration was to scale up the account in terms of conversions while keeping the Cost Per Acquisition at the same level. 

In terms of conversions, we saw a large increase of +40% (August versus November). Moreover, also the quality of conversions increased, which resulted in more Sales Qualified Leads. With the result being a full sales pipeline and a lot of introduction calls for the sales team.

Besides growing the number of conversions, the CPA was also an important metric. The objective was to keep the CPA stable based on the historical CPA of August. Keeping this CPA target means that we could slowly raise the monthly budget from September onwards. If we compare August to November we not only hold the CPA target, but we were able to lower the CPA by -16%. Which means that we were able to get conversions more cheaply.


In the past online marketing agencies were hired for taking over the entire SEA execution. Nowadays companies want more in-house knowledge and hire online marketing agencies for more strategic needs. This case shows how a good collaboration structure resulted in a very effective and efficient way of optimizing the SEA account of Sentinels. As a result, the number of conversions increased by +40%, while the CPA decreased by -10%. Curious about how we can implement this same collaboration structure for your company? Contact us for more information!

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Working with Pure Digital was like extending our in-house team. Jeroen was always there when I needed him – super responsive and constantly on top of new trends in paid search. His keen eye for detail and innovative approach were essential in achieving our outstanding results. Pure Digital was not just an agency to us; they were committed, proactive, and integral to our success. Their passion and alignment with our vision set them apart, making them a true partner rather than just a service provider. I wholeheartedly endorse Pure Digital for anyone looking for more than just an agency.

Nikiforos Aslanoglou