How to Write Agency Case Studies That Win Work

A strong case study is one of an agency's best sales tools. It shows prospects what working with you looks like and proves you can deliver. Most case studies, however, read like vague project summaries.

Choose the right projects

Pick projects with a clear problem, a thoughtful approach and measurable results, ideally for clients similar to the ones you want more of.

Get permission early

Agree with the client at the start of a project that you may write a case study. For white-label work, make sure you only publish what your contract allows.

Use a clear structure

1. The client: who they are, in a sentence or two.
2. The challenge: what problem they faced and why it mattered.
3. The approach: what you did and why, including key decisions.
4. The result: measurable outcomes with timeframes.
5. The client's view: a genuine quote, approved by the client.
6. What's next: ongoing work or lessons learned.

Make results specific

Concrete numbers, compared with a baseline, are far more persuasive than adjectives. Only use figures you can verify and that the client has approved.

Tell a story

Readers connect with people and decisions. Describe the obstacles, the turning points and what made the difference.

Keep it scannable

Use headings, short paragraphs, a summary box with key results and visuals such as screenshots or before-and-after images.

Put case studies to work

Link to them from service pages, include them in proposals, share them on social media and send them in follow-up emails.

Need writers?

oceanone's specialist copywriters can turn your project notes into persuasive case studies.