What Makes a Great Agency Case Study with Joel Klettke

Gray MacKenzie talks with Joel Klettke, founder of Case Study Buddy and a conversion copywriter who has built an entire business around turning client success into compelling stories. Joel founded Case Study Buddy in 2016 after working in SEO agencies and transitioning into conversion copywriting. The company now serves clients including HubSpot, Docebo, Varonis, and WP Engine, producing case studies that go far beyond the typical “challenge-solution-results” template.

Why Case Studies Are Irreplaceable Social Proof

Joel makes a direct argument for why agencies should prioritize case studies over almost any other type of content: they represent social proof that competitors cannot replicate. A blog post about strategy can be copied. A case study documenting specific results you delivered for a specific client is uniquely yours.

For agencies, this matters because prospects are evaluating multiple firms that all claim to deliver results. Case studies provide tangible evidence that moves conversations from “we can do this” to “here is proof that we have done this for someone like you.” Joel points out that narrative case studies consistently outperform generic metrics in sales conversations because they give prospects a story they can relate to, not just numbers on a slide.

He also highlights that for most agencies, the About page is one of the top three most-visited pages on their website. Yet most agencies fill it with generic language about their team and values. Joel recommends using customer stories and language on the About page to demonstrate value alignment, because prospective clients care more about how you serve people like them than how many awards you have won.

The BDA Framework for Better Interviews

Case Study Buddy uses a structured interview framework called BDA - Before, During, After - rather than rigid scripts. Trained interviewers who understand storytelling principles guide conversations through three phases, knowing where to probe deeper based on the responses they hear.

In the Before phase, the interviewer explores what the client’s world looked like prior to the engagement. Joel emphasizes that great challenge sections go beyond “what was broken” to explore the emotional and business impact. “You want to talk about mistakes. What would happen if this hadn’t gotten solved?” The stakes are what make a story compelling. If the problem was inconvenient but not consequential, the case study lacks tension.

The During phase focuses on the why behind decisions, not just the what. Rather than listing deliverables, a strong case study explains the reasoning behind the agency’s approach. Why did you choose this strategy over alternatives? What made this client’s situation require a different approach? This is where the agency’s expertise shines through naturally.

The After phase moves beyond metrics to impact. Joel notes that “the worst results section you can have is like an analytics graph.” Instead, strong results sections explain what became possible after the engagement. The client could expand into a new market. They freed up executive time that was previously spent managing the problem. They secured additional funding based on the improved numbers. Impact resonates more than data alone.

Separating Interview From Writing

One of Case Study Buddy’s process decisions that Joel highlights is separating the interviewing role from the writing role. Interviewers focus on drawing out the full story and identifying narrative gaps. Writers focus on crafting that story into a compelling piece. Account managers and project managers handle the logistics of scheduling, approvals, and follow-up.

Joel candidly shares that the hardest part of case study production is not the creative work - it is the project management. Getting clients to agree to participate, scheduling interviews, securing approvals from legal and marketing teams, and managing the back-and-forth revision process takes persistent effort. Agencies that try to produce case studies without dedicated project management typically stall out after the first round of interviews.

Case Studies as Multi-Format Assets

Modern case studies should generate far more value than a single PDF or webpage. Joel explains that Case Study Buddy treats every case study as a source asset that produces multiple content formats - written narratives, video testimonials, audiograms for social media, one-page sales sheets, and pull quotes for email campaigns.

This multi-format approach maximizes the return on the investment that goes into producing each case study. A single customer interview can yield content for every stage of the funnel and every channel the agency uses. Joel positions case studies as “full funnel assets” rather than bottom-of-funnel only, because the stories, quotes, and proof points they contain are valuable anywhere a prospect might encounter the brand.

Resources Mentioned

• Joel Klettke on LinkedIn - Founder of Case Study Buddy
• Case Study Buddy - Productized case study creation service
• Business Casual Copywriting Newsletter - Joel’s newsletter on conversion copywriting
• Descript - Visual audio/video editing and transcription tool
• KlientBoost - Referenced as an example of effective case study filtering