How to write a consulting case study that sells.

Most solo consultants have no case studies, or they have a line on their website saying they helped a client in the financial sector improve operations by 30 percent. No name, no company, no reason for a skeptical corporate buyer to believe it.

Carla Cherry, who has built offers with hundreds of ex-corporate consultants at Power Offer Consultants, puts the failure earlier than the writing. The consultant produced the result. What they cannot do is translate a result they produced inside a company into a result they now sell, still talking from what Carla calls resume mode instead of showing what they can now do for someone else.

They also underrate their own record badly enough that the material has to be pulled out with an exercise rather than asked for: in her program, a case-study exercise runs inside the first two calls, alongside the buyer persona exercise, built to show a new consultant what they are actually capable of.

This guide covers how to write case studies a corporate buyer acts on, using the method she teaches. Every example cited is a named person with a confirmed outcome.

Power Offer Consultants helps ex-corporate experts package their expertise and sell it to corporate. If you need to learn how to use case studies to find clients, see the guide to getting consulting clients.

Why do case studies matter more than testimonials for corporate buyers?

A testimonial is a statement of satisfaction, and it works for individual buyers making emotional decisions. A corporate buyer runs a narrower check: has this person solved my specific problem before, done it more than once, and gotten a result that looks like mine.

Her VSL puts it from the consultant's side, under polished perception: you must be perceived by the marketplace to solve the specific problem, to have done it many times, and to have results that are proven and transferable. Her own version of the buyer's question: "Have they seen proof that I've done this before? Have they seen a result that looks like their problem?"

A case study is how a buyer answers both questions without calling you first. It is also what a corporate buyer carries into their own process: the problem they can verify looks like their own, the approach they can judge for fit, and the result they project a return from. A procurement team reading a case study is building the internal business case for hiring you.

Carla's test for whether a result belongs in that document is whether the buyer's finance team would recognise it. Her standard is blunt: "High value consulting = results that hit the P&L." A result that improved morale or tidied a process is real work, and it is not the number that gets a budget approved. Find the version that touched revenue, cost or risk.

The structural advantage

A testimonial on your profile is seen by people who already found you. A case study published as a standalone page reaches people searching for the problem it describes.

Case studies also decide your pricing ceiling. In Carla's three-tier offer structure the enterprise tier is gated on proof: "Build this after you have 2-3 case studies from Tier 2." The smaller implementation engagements come first because they manufacture the evidence the six-figure engagement needs.

For how to structure the sales conversation around case studies, see the guide to selling consulting services.

Do this next:

1. Rewrite your strongest client result as the version that hits the P&L: revenue gained, cost removed, risk retired.

2. Count your finished case studies. Under two, drop the enterprise pitch and go win the tier below it.

What is the Challenge-Solution-Outcome framework?

Every strong consulting case study carries three sections, in this order, whether or not the labels appear on the page.

Carla's format rule for offers is the rule that makes a case study readable: "Every single phase needs a before state and an after state." Her worked example moves the client from not knowing where they are bleeding money to a full audit naming the three areas costing them $400k a year. Every section gets a state before it and a state after it, and the last state carries a number.

Challenge

The client's situation before working with you: what problem they faced, what they had tried, and what it cost them in revenue, time, talent or prospects.

A manufacturer struggling with operational efficiency is too vague. A manufacturer losing $1.2 million a year in inventory carrying costs because vendor onboarding took 90 days instead of 30 gives the reader enough to judge fit. The challenge section is where the prospect recognises themselves, and if it does not sound like their situation they leave, which filters the wrong buyers out early.

Solution

What you did: the specific actions, the length of the engagement, and what the client had to do on their end.

Carla runs a test on offers that applies here: say what changed between day one and day ninety without the three consulting abstractions she bans, strategy and optimize among them. If you cannot, what you have is "a vague promise wrapped in corporate speak", and the buyer learns nothing about whether your method would work in their organisation.

Outcome

Named person, named company, specific number. Ron N. of IRON Personal Services and Consulting booked about $425,000 in contracts within two months. That is a result. Significant revenue improvement is not.

Her Big Promise, the four-part line she puts at the head of an offer, is a good test for that sentence too: the action you took, the outcome with a number or a range, the timeline, and the mechanism. Miss the number and the buyer cannot price the engagement. Miss the timeline and they cannot map it to a budget cycle.

A pitch she rewrote for a former McKinsey consultant shows how tight that line can get once it starts from the problem. Eight months of selling "strategic transformation consulting" had produced nothing.

The same expertise stated as a problem with a deadline, "I help PE portfolio companies complete system integration in 90 days so you can show growth metrics at your first board meeting", put her in conversations with three private equity firms. Her diagnosis of the first version: a generic solution looking for a problem.

Do this next:

1. Write a before state and an after state for each section, and put a number in the after.

2. Rewrite the outcome sentence until it holds four things: the action, the number, the timeline and the mechanism.

How do you get permission to write case studies?

The barrier is the permission, not the writing. Many consultants assume clients will refuse, so they never ask.

Carla's answer is to stop asking for the case study afterwards and make it part of the deal. In one of her launch posts she describes a soft launch with early clients told plainly what they are: you are among the first, and you are helping build the results and the feedback the practice needs. Where a soft launch fits, say it up front and the case study stops being a favour and becomes the trade.

Her reason is what the proof has to be when a prospect asks whether the work is real. You answer with your own clients and your own numbers, "Not theoretical results or borrowed case studies." Those first clients are what buys that answer: real proof instead of theory. Her broader line to consultants leaving corporate stays the same: play big from the start.

When to ask

Ask when the result is fresh and the client is pleased: the final debrief, or the moment they share a milestone. Offering to send the draft for approval first removes most objections.

How to handle confidentiality concerns

Many corporate clients have policies about endorsing vendors publicly. That does not block the case study, it sets its form. Three versions, strongest first:

Named with approval. The client reviews and approves before publication. Named results from named companies are the strongest proof in consulting.

Named person, anonymised company. A former VP at a Fortune 100 financial services firm keeps the credibility and respects the policy.

Fully anonymised with specifics. Industry, company size and outcome numbers, no name. A $500M manufacturer that cut vendor onboarding from 90 days to 30 and saved $1.2M a year is the weakest version and far better than nothing.

Do this next:

1. If a soft launch fits your stage, tell your next two clients plainly that they are your source of proof, and put the case study in the terms.

2. Book the case-study conversation into the final debrief instead of chasing it weeks later.

How do you write a case study when you only have one engagement?

Most consultants start with one or two engagements. One strong one is enough.

One is enough to start

Kendra B., a VP of Elevation Real Estate with deep expertise in multifamily property management, earned $6,000 in her first week as a consultant for a three-hour workshop. One engagement, one result, and it answers every prospect in that industry asking whether this has worked for someone like them.

Using your corporate career as proof

If you have just left corporate and have no consulting engagements yet, your corporate results are your case studies. Carla gives this correction flatly: "You led a team of 27 in corporate. That counts. Stop downplaying it." Her point is that the case studies already exist, made inside the corporate years themselves. What changes on the way out is the hat you wear while you sell it.

Mike M. of Buckeye Business Performance says he worked on Victoria's Secret PINK as it went from startup to $1 billion in sales in its first three years, a corporate credential most consultants would trade for. On its own it did not close his consulting deals: he had leads and conversations, and was spending both on the wrong people, finding out on the second call. A credential on its own does not close the deal.

What changed the outcome was one qualifying question that sorted prospects before the call went long, and three high-ticket closes followed within two to three months. Lead with the role you held and the initiative you ran, then build the qualifying question that tells you fast whether the person on the call is the one that result is for.

Mine what you already have for the offer

Carla's more useful move is to read your existing case studies for the one fact that should become your positioning. A client of hers was selling broad branding services to household names. Going back through his work she found he had helped take two companies public while doing their branding.

He now brands companies preparing for IPO, targeting private-equity and venture-backed companies at Series A and beyond, where a six-figure fee is expected because the work has to speak to shareholders. Her summary: "Same guy and same skills, completely different offer."

The same rule applies to the part of your history you find least relevant. Bonnie K. of Video Magic Productions had been leaving a James Bond film, Days of Our Lives and Charlie's Angels out of her introduction because none of it was current work. It was the least copyable thing she had.

See the guide to starting consulting after corporate for the transition, and the guide to packaging consulting services for the package a case study sits inside.

Do this next:

1. List every result you produced inside corporate with a number attached, including the ones you assume do not count.

2. Read the list for the one fact that could become a specific offer, the way two IPOs became an IPO branding practice.

What should a case study look like for a corporate audience?

Carla's own case-study posts follow one shape, and it is the shape to copy: the credential that makes the failure surprising, the specific thing that was wrong, the single change she made, the figure, and one line of transferable lesson.

Her post about Mike opens on the credential, "He took a brand from launch to $1B in three years.", then turns straight to the fact that he could not close his own consulting deals. The reader holds the contradiction before any method appears.

Lead with the number

Put the result number in the headline or the first sentence. It mirrors a question Carla asks on her own qualifying calls, pushing a prospect to name the largest result tied to money they can point to, from corporate or from their own company. Biggest win first, unpacked afterwards. Write the case study the same way round.

Keep it to one page

Two or three paragraphs for the challenge, two or three for the solution, one or two for the outcome. If you need more space, the problem description is too generic.

Include the timeline and the reaction

Corporate buyers think in fiscal quarters, so a result reported in two months or 120 days maps to their planning horizon. A result with no timeline is an anecdote.

Then add the part nobody can invent: what somebody else said when it landed. The line Carla uses from Brittany W.'s $86,000 weekend is not the figure. It is "And her CEO asked who taught you what you're doing." A third-party reaction is the hardest line in a case study to fake.

Make it verifiable

Give enough detail that a skeptical buyer could check the claim. Elle R. of Coastal Creative Consulting, an event planner who has worked with Spotify, had four calls set up within 36 hours of her launch, and within a week was asked for a proposal by the organizer of an invitation-only summit in Washington, DC. Person, company and timeline are checkable. That checkability is what separates a case study from marketing copy.

Do this next:

1. Rewrite the opening line as the credential plus the contradiction, then the number.

2. Ask your client what their boss or their board said when the result landed, and quote it.

A one-page consulting case study template

Copy this structure onto one page. Every line comes from the sections above; fill it with one client and one result.

1. Headline: the number. The biggest win, stated first, with the person and the company named: [client name], [company]: [result with a number] in [timeline].
2. The credential and the contradiction. One sentence on who the client is, and the thing they could not do before.
3. Challenge, two or three short paragraphs. The buyer's problem in the buyer's words, on their timeline, and what it cost in revenue, time, talent or prospects. This is the before state.
4. Solution, two or three short paragraphs. What you did, how long it took and what the client did on their end: what changed between day one and day ninety, in plain words.
5. Outcome, one or two paragraphs. The action, the number, the timeline and the mechanism. This is the after state.
6. The reaction. One line quoting what someone else said when the result landed: a boss, a board, a buyer.
7. The check. The details a skeptical buyer could verify: person, company, timeline.

How do case studies fit into the consulting sales process?

Case studies are sales tools used at specific moments, and Carla's method puts most of their work before the call rather than during it.

Before the call

Send the matched case study with the booking confirmation. Carla calls this credibility builders: collateral sent ahead of a first conversation so the prospect arrives already reading you as the person who solves this, the problem already diagnosed before either of you says a word, and the call opens from authority rather than introductions.

Her standard for everything else the buyer can see is that having worked in the industry is not proof; the market has to see you producing this specific result, repeatedly. Your profile, your site and your posts are part of the case study whether or not you meant them to be.

During the industry-match objection

Carla gets this question often enough on her own sales calls that she has a standard answer ready for whether she has experience in the caller's specific industry. Her answer is almost always yes, backed by named clients in the caller's industry, and she explains why her method travels: getting a corporate buyer who is paid to say no to say yes is the same skill across rooms, fintech to construction to biotech.

For your own case studies, keep them sorted by industry so the match is ready when the question comes. Match the industry if you have it, or match the adjacent one and name the transferable parts.

If you have neither, Carla's substitute is research. Cam B. of The Frequent Speaker interviewed decision-makers across ten organizations, Bell Canada, Amazon, Rakuten, Kobo, Harvard, Discover Financial, PwC and Benjamin Moore among them, compiled the findings into a white paper and sent it back to every participant.

What it bought him was the ability to say, in his words, "look, this is not just data out of my head. This is information that I've received from these clients, these potentials." A consultant with no client results yet can still walk in carrying that many conversations.

In the proposal

Carry the matched case study as an appendix, so the buying committee has something to evaluate beyond rates and deliverables. The proof count also decides your scope: two or three case studies is what lets you propose the enterprise engagement rather than the audit.

Do this next:

1. Attach one matched case study to every booking confirmation, with two lines on why you picked it.

2. Read your LinkedIn profile against that case study. If the same result is not visible in both, fix the profile.

3. With no matched proof, run research interviews in the target industry, the way Cam did, and publish what you learn.

Frequently asked questions

How many case studies do I need?

Start with one. One strong, named, verifiable case study beats ten anonymised ones. The count that matters is the gate on your top tier: Carla builds the enterprise offer only after two or three case studies exist from the tier below. Three to five across different industries will match most prospects.

Can I write a case study about pro bono work?

Yes. The buyer cares about the result, not whether you were paid. Carla treats a consultant's first clients as a deliberate source of proof: told plainly that they are among the first, in exchange for the result and the feedback. Her broader line to consultants leaving corporate stays the same: play big from the start.

What if the result is qualitative, not quantitative?

Qualitative results work if they are specific. Redesigning a leadership team's decision process so meeting time halved and three delayed launches unblocked is credible. Improved team dynamics is not. Carla's day-1-to-day-90 test is the filter: say what changed between day one and day ninety without abstractions.

How often should I update my case studies?

Update when new results land. Ashley R. of Goldinage Retirement Coaching pivoted her target market to wealth advisors and saw 9 of 10 interview calls convert to interested follow-ups within weeks, worth documenting while her practice was moving.

Should case studies go on my website or stay private?

Both. Publish the strongest one or two, and keep the full set in a portfolio you share selectively in sales conversations. Some corporate clients approve private use but not publication, and respecting that distinction is what gets you more permissions later.