Marshfield Clinic: 454% CTR gain from schema markup

Most structured data case studies quote a single headline percentage with no name attached. Schema App’s customer story on Marshfield Clinic Health System, a healthcare provider with over 60 locations across Wisconsin and Michigan’s Upper Peninsula, names the client and states two separate click-through rate figures tied to two separate schema efforts. Here is exactly what the source says, and what it leaves unsaid.

What the case study states#

Two figures, two different causes. The published story states plainly: “Across all physician URLs, when a Review Snippet was awarded, CTR increased by 454%.” Separately, it states that “Marshfield Clinic’s physician pages saw a 32% increase in click-through rate” after Schema App’s External Entity Linking feature was implemented, which links entities such as medical specialties to Wikipedia, Wikidata and Google’s Knowledge Graph. These are not the same intervention: one is about earning a Review Snippet rich result, the other is about disambiguating what a page is about for search engines.

Why the project started. The case study is explicit that the trigger was a decline, not a gain: “During a review of organic search traffic from 2021 to 2022, Katie observed a 30% decline in organic traffic.” Marshfield Clinic’s Lead Digital Marketing Strategist, Katie Schneekloth, and her team then began evaluating structured data at scale as part of the response.

What the case study does not state#

No baseline CTR, no exact dates. Schema App reports the size of the lift for both the 454% Review Snippet figure and the 32% entity linking figure, but does not publish the starting click-through rate, the resulting click-through rate, or the exact weeks or months each figure covers. The story places the Review Snippet gain as a year-over-year comparison, without a stated start and end date.

A vendor-published success story, not an independent audit. Schema App wrote and published this case study about its own client relationship and its own product feature. That does not make the percentages false, but it means the case study was selected and framed by the vendor whose product produced the result, the same limitation that applies to Google’s own structured-data success stories.

Why we care#

Cite what is actually verifiable. “Schema App reports a 454% CTR increase for Marshfield Clinic’s Review Snippet pages” is a claim this article can stand behind, because it is a direct quote from Schema App’s own published page. “Schema markup increases CTR by 454%” is not defensible, because it drops the fact that this is one client’s Review Snippet result, not a general multiplier any site adding schema markup should expect.

Two levers, not one. The case study is a useful reminder that “structured data” is not a single lever: a Review Snippet earned through review markup and entity linking through sameAs and Knowledge Graph references are different mechanisms with different prerequisites, and this source credits each with a separate, distinct number rather than folding them into one blended figure.