Arke x IMB

The Independent Monitoring Boards (IMB) are nonprofit independent scrutiny bodies made up of volunteers who monitor prisons and immigration detention facilities and help promote fair and humane treatment.

The IMB volunteers play an important public service role by speaking with and hearing from those in these facilities, and their work supports accountability and transparency across prisons and immigration detention facilities.

With the task to help the IMB recruit more volunteers, we began a two-phased campaign aimed at increasing volunteer applications whilst improving efficiency YoY.

The Challenge

Our objectives were to increase YoY applications whilst tracking other KPIs:

• Application clicks
• Total applications
• Maintaining CPAs below previous benchmarks

The baseline we aimed to improve upon was:

• 210 application clicks
• 104 applications

The Audience

To ensure our ads were seen by relevant local audiences, we prioritised targeting people actively interested in volunteering who were located near prisons and immigration detention facilities. This included:

• Volunteering and civic-interest audience
• Retiree and community-focused demographics
• Users actively exploring relevant opportunities

The Strategy

Building on previous learnings, our strategy has evolved from broader targeting to more targeted local recruitment activity.

A high-intent keyword strategy was implemented and focused on audience quality over scale to drive more meaningful engagement. We also built brand awareness and understanding of the IMB role as our research helped identify a gap in the market to build their brand.

To activate this, we used a multi-channel recruitment approach, leveraging Meta to drive awareness, consideration and trust, Google Display to build scale and visibility, and Google Search to reach people actively searching for volunteering opportunities and drive conversions.

We executed continuous retargeting throughout the funnel to nurture users showing high intent and improve recruitment efficiency.

We used Meta as our primary conversion channel refining audience segmentation and geographic prioritisation throughout the campaign. Furthermore, we structured messaging frameworks using phrases like “promote fair treatment” and “help promote fairness” to appeal to our target audience.

Our creative approach was informed by campaign data and previous insights, with testimonial-led assets to drive trust and authenticity. A/B testing showed that messaging focused on fairness, accountability and community impact generated the strongest engagement, while ongoing optimisation and demographic alignment pushed top creatives to CTRs above 2.5%.

We monitored performance data, rapidly identifying the most effective channels and reallocating spend accordingly. By removing low-efficiency audiences and keywords and focusing on high-intent, local users, we not only maintained but exceeded KPIs despite reduced investment.

Our analysis of long-term search behaviour provided clear evidence of when demand for volunteering opportunities is highest, enabling us to make informed, data-driven decisions on campaign timing and investment. By aligning activity with identified peaks during Q1, we enhanced visibility, reached audiences during periods of increased interest in volunteering opportunities, and drove stronger overall performance.

The Challenges

The entire sector has been facing budget cuts, and the IMB was equally impacted with a year-on-year reduction in media budget. However, our campaign expectations were higher.

With limited creative budget and public sensitivity around prisons and immigration detention facilities, we prioritised message testing and audience alignment, leveraging testimonial-led content proven to resonate.

Tracking limitations beyond the “Apply” click presented a further challenge, as conversions occurred on a third-party site. To maintain a data-led approach, we validated performance against the IMB’s backend data.

The Results

The campaign exceeded recruitment targets while improving efficiency at both a national and local level. By aligning targeting, messaging and budget to priority geographies, we ensured activity translated into meaningful recruitment outcomes.

Across all channels, the campaign generated:

• 667 applications (+548% YoY)
• 3.68% conversion rate (up from 2.88% YoY)
• 0.50% CTR, nearly double the expected performance
• 3.3M impressions (+603% YoY)
• 19,000 clicks (+124% vs benchmark) with strong engagement quality

The Impact

In a time when conversations around prisons are sensitive and public sector budget cuts have been declining for years, our campaign focused on bringing in high-intent audiences for a cause that is an important public service role.

The campaign delivered proven real-world outcomes, generating 667 confirmed volunteer applications, representing an increase in applications of 548% YoY with a similar budget in place.

This campaign demonstrates how targeted recruitment activity can support public sector volunteer engagement efficiently. Even when external factors such as public perception and media reporting create additional challenges for organisations operating in sensitive sectors.

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