You prove a marketing claim happened by attaching it to specifics that could not exist unless it were true. A claim like "our customers see faster results" proves nothing, because it costs nothing to write and describes no actual event. The proof is in the particulars: which customer, what they measured, when, and what changed. Specificity is not decoration on the claim. Specificity is the proof, because invented specifics fall apart and real ones hold up.

The concrete moves:

• Name the actor. A real customer, a real person, a real deal. "A manufacturer in the Midwest" beats "our customers." A named account, where you can use it, beats that.
• Attach a number that moved. Not a rounded marketing statistic, the actual figure and the actual before-and-after. Precise numbers read as recorded; round ones read as manufactured.
• Anchor it in time. A date, a quarter, a sequence of events. Things that happened have a when, and claims that avoid a when signal that nothing did.
• Show the mechanism. Not just that a result occurred but how, so the outcome connects to something the reader can follow rather than a leap they have to take on faith.

This is what separates a history from a claim. A claim asserts. A history recounts something that occurred and leaves evidence a skeptic could check. In a market where any claim can be generated for free, the only marketing that still moves people is the kind that shows its work, because showing your work is the one thing a fabricated claim cannot do.