How to Implement NPS for Agencies: FINALLY Agency Case Study with Amber Mackay

Gray MacKenzie interviews Amber Mackay, Head of Client Services at FINALLY Agency, about implementing Net Promoter Score as a core metric for agency client success. FINALLY is a UK-based inbound marketing agency specializing in engineering and manufacturing, a Platinum HubSpot partner with approximately 25 active clients. In this episode, Amber walks through exactly how FINALLY implements NPS - from the survey mechanics to handling detractors to converting promoters into case studies.

Why NPS Matters for Agencies

Net Promoter Score measures one thing: how likely a client is to recommend your agency to someone else. It is a simple question on a scale of one to ten, but the implications run deep. Clients who score 9-10 are promoters - they are actively advocating for your agency. Clients who score 7-8 are passive - satisfied but not enthusiastic. Clients who score 0-6 are detractors - they have concerns that could lead to churn or negative word-of-mouth.

At the time of recording, FINALLY Agency’s NPS score sits at 80 across approximately 25 surveyed clients. That is an exceptionally strong score, and Amber attributes it to two factors: consistently good work and a feedback culture that catches problems early. The score itself matters less than the system that produces it - a regular cadence of honest conversations with clients about how the agency is performing.

The Manual Survey Approach

One of the most counterintuitive aspects of FINALLY’s NPS implementation is that it is entirely manual. There are no automated email workflows or survey tools sending out forms. Instead, Amber and her account management team ask the NPS question directly during client calls.

For retainer clients, the question comes up during quarterly review meetings. For project-based clients, it happens at project delivery. The phrasing is conversational - sometimes “On a scale of one to ten, how likely are you to recommend us?” and sometimes as simple as “How much do you love us?”

This manual approach generates significantly higher response rates than automated alternatives. When a real person asks the question in the context of a real conversation, clients are more willing to give honest, detailed responses. The feedback is also richer because the account manager can follow up immediately with probing questions about what is working and what is not.

Setting Expectations Early

Amber emphasizes that NPS surveys should not feel like a surprise to clients. FINALLY sets the expectation during onboarding that regular feedback check-ins are part of how the agency operates. When clients know from the beginning that they will be asked about their experience, the surveys feel like a natural part of the relationship rather than an intrusion.

This framing also positions the agency as client-focused from day one. It signals that FINALLY cares about outcomes, not just deliverables - and that they are confident enough in their work to invite honest feedback on a regular basis.

Handling Detractors

When it comes to detractors, Amber makes an important observation: they are almost never a surprise. Agencies that are paying attention to their client relationships can usually sense dissatisfaction before a formal NPS survey confirms it. Changes in communication patterns, delayed feedback, or reduced enthusiasm during calls are all leading indicators.

When a detractor is identified - whether through the survey or through daily interactions - FINALLY schedules a separate follow-up conversation to isolate and address the concerns. This is not a quick chat at the end of a status call. It is a dedicated meeting focused entirely on understanding the client’s perspective and developing a plan to improve.

The agency also conducts project retrospectives regardless of outcomes. Win or lose, every significant engagement gets a structured review that surfaces what went well and what could improve. This discipline means the agency is learning from every engagement, not just the ones that generate complaints.

Converting Promoters into Business Development Assets

The flip side of detractor management is promoter strategy. When clients score 9 or 10, FINALLY has a systematic process for converting that enthusiasm into business development assets.

The first step is gathering testimonials for the website and LinkedIn. Written quotes from satisfied clients carry significant weight with prospects who are evaluating agencies. The second step is developing written case studies that show before-and-after results with specific metrics and client quotes. The third step is capturing video content during existing client interactions - leveraging the positive sentiment while it is fresh.

These assets compound over time. A library of strong case studies and testimonials makes every sales conversation easier because prospects can see evidence of results rather than relying on the agency’s claims about its own capabilities.

Beyond NPS - Building a Metrics Culture

Amber closes by noting that NPS is one piece of a broader metrics culture at FINALLY. The agency tracks NPS alongside marketing leads generated, financial performance, content production numbers, and business development metrics through an EOS scorecard approach. Each metric provides a different lens on business health, and together they give leadership a comprehensive view of how the agency is performing.

The key insight is that no single metric tells the full story. NPS captures client sentiment. Financial metrics capture profitability. Production metrics capture throughput. An agency that tracks all three dimensions can make better decisions than one that optimizes for any single number.

Resources Mentioned

• Amber Mackay on LinkedIn - Head of Client Services, FINALLY Agency
• FINALLY Agency - UK-based inbound marketing agency
• FINALLY Agency Case Studies - Client results and success stories
• The Engine Room - FINALLY’s webinar and podcast series
• Retently - NPS survey tool
• FINALLY NPS Blog Post - Amber’s guide to NPS