Customer case studies are stories a vendor tells about a client it helped, and a buyer should treat each one as a claim to check, not as proof. A good case study names the client, gives dates, shows numbers and explains how they were measured. A weak one hides all four. This guide gives you a short way to tell the two apart.
The advice below is for buyers who read vendor stories during a software, services or agency search. It draws on US Federal Trade Commission (FTC) rules for endorsements and for the proof behind ad claims. Those rules bind advertisers, but they also work as a plain checklist for any reader.
Why case studies are marketing
A vendor writes its own case studies. It picks the happiest client, the best quarter and the most flattering number. That is normal, but it means the story is an ad.
The FTC treats a customer story in an ad as an endorsement. Under its Endorsement Guides, an endorsement must reflect the honest opinions, findings, beliefs or experience of the endorser. It also may not be taken out of context or reworded so that it distorts the endorser's view. A vendor may not say "the client said this" unless the client really did.
The same rules say an advertiser can be responsible for misleading statements made through endorsements. So a reputable vendor has a reason to keep its stories accurate. A buyer still needs to look for the signs.
Sources: FTC, 16 CFR 255.1, General considerations (Endorsement Guides, revised 2023)
Check the named client
Start with who the story is about. Look for these points:
- A real name. "A leading retailer" tells you nothing. A named company, with a named contact and title, can be checked.
- A current relationship. The FTC says that when an ad shows the endorser uses the product, the endorser must have been a real user when the endorsement was given. The advertiser should also have good reason to believe that is still true. Ask whether the client still uses the vendor.
- Approval. A quote in quotation marks should be the client's exact words. The Guides say an ad should not present reworded words as exact words.
If the vendor will not let you speak with the client, ask why. A willing reference is one of the best signs you can get.
Sources: FTC, 16 CFR 255.1(b) and 255.1(c), General considerations
Check the dates
Old results do not describe today's product. Look at three dates: when the work happened, when the results were measured, and when the page was last updated.
The FTC says an advertiser may use an expert or celebrity endorsement only while it has good reason to believe the endorser still holds the views shown. It can do this by asking again at reasonable intervals, and new information about the product or a material change in it is a reason to ask. For you, the lesson is simple. If the story is several years old, ask whether the product, the team or the price has changed since then.
Also check the size of the client. A result at a company with 20 staff may not carry over to one with 2,000.
Sources: FTC, 16 CFR 255.1(b) and 255.1(c), General considerations
Check the numbers
Numbers sell. They are also where weak stories fail. Ask these questions of every figure:
- What was measured, and over what period?
- What was the starting point? A rise from a very low base can sound large.
- Who measured it, the client or the vendor?
- Was anything else going on, such as a price cut, a new hire or a seasonal peak?
The FTC's policy on ad substantiation says advertisers must have a reasonable basis for objective claims before they run them. It also says that when an ad claims "tests prove" or "studies show," the firm should have at least that level of support. So a vendor that claims a result should be able to show how it got there.
One more point matters here. Under the Endorsement Guides, an ad that shares one customer's experience on a key point will likely be read as saying other customers can expect the same. If the vendor lacks proof of that, it should clearly state what results are generally expected. Look for that line. If there is none, ask for the typical result, not the best one.
Sources: FTC Policy Statement Regarding Advertising Substantiation (1984); FTC, 16 CFR 255.2(b), Consumer endorsements
Check who benefits
Ask whether the client has a tie to the vendor. A client who gets a discount, free service, a fee or a referral reward may speak warmly for that reason. The Guides call this a material connection. They hold advertisers responsible for failing to disclose unexpected material connections with their endorsers, so a buyer can fairly expect a plain note about any such tie.
The Guides also make clear that the endorsement must reflect real experience. If the story reads like a script, treat it as one and ask for a direct call.
Sources: FTC, 16 CFR 255.1(d), General considerations
A quick checklist
- Is the client named, and will it take your call?
- Is the date of the work and of the results clear?
- Does each number say what was measured, by whom, and over what period?
- Is the client's size and need close to yours?
- Is any link between client and vendor stated?
- Does the vendor give a typical result, not just the best one?
A vendor that passes most of these has earned a closer look. A vendor that fails several has given you its answer.
Sources: The checklist is the editors' summary of the points above.
Sources
- Federal Trade Commission, 16 CFR Part 255, Guides Concerning the Use of Endorsements and Testimonials in Advertising (revised July 2023). law.cornell.edu
- Federal Trade Commission, FTC Policy Statement Regarding Advertising Substantiation, 1984. ftc.gov