How to Write Case Studies That Win New Business

A well-written case study is one of the most powerful pieces of content a service business can publish. It shows prospective clients exactly what working with you looks like, the problems you solve, and the results you produce — all through the lens of someone who’s already been through it.

Yet most case studies fail to do this. They’re either too vague ("we helped a client improve their business") or too technical ("we implemented a multi-channel attribution model"). Here’s how to write case studies that actually influence buying decisions.

Use the problem–solution–result structure

The classic format works because it mirrors the reader’s own situation. Start by describing the client’s problem in enough detail that a similar prospect recognises themselves: what was going wrong, what they’d already tried, and why it mattered to them. Specificity here is everything — "a Norwich accountancy firm struggling to generate website enquiries" is far more relatable than "a professional services client."

The solution section should explain what you did without excessive technical detail. Focus on the decisions you made and why, not on listing every deliverable. This is where you demonstrate expertise and judgement — the qualities a prospective client is really buying.

The result section is where most case studies fall short. Vague results ("the client was very happy") are almost worthless. Wherever possible, use numbers: "enquiries increased by 40% in the first three months" or "average page load time dropped from 8 seconds to 1.4 seconds." If you can’t share exact figures, use directional language: "nearly doubled," "reduced by more than half."

Include a client quote

A direct quote from the client transforms a case study from a self-congratulatory piece into genuine social proof. The quote doesn’t need to be effusive — in fact, a measured, specific quote ("They delivered exactly what they promised and the results have been clear") is often more credible than exuberant praise.

Ask the client for a quote as part of your post-project review. Explain that it will appear on your website alongside a brief description of the project. Most satisfied clients are happy to help, especially if you draft a version for them to approve — it removes the effort barrier on their side.

Always attribute the quote to a named person with their job title and company (with permission). Anonymous testimonials carry far less weight than those attached to a real name and context.

Make case studies easy to find

The best case studies in the world do nothing for your business if visitors can’t find them. Create a dedicated "Case Studies" or "Our Work" section in your navigation, and link to relevant case studies from your services pages. A visitor reading about your website design service should be able to click through to a real example of a website you’ve designed.

Consider which sectors or services you most want to win more work in, and prioritise case studies in those areas. If you want more restaurant clients, publish a restaurant case study first. The closer the match between a case study and a visitor’s own situation, the more persuasive it is.