--- title: "Marketing Expert Was Allowed to Opine on Trademark Dilution" meta: "og:description": "The marketing expert was allowed to testify because his testimony addressed consumer impressions of the Hyundai Motor brand" "og:title": "Marketing Expert Was Allowed to Opine on Trademark Dilution" author: "Expert Witness Profiler" description: "The marketing expert was allowed to testify because his testimony addressed consumer impressions of the Hyundai Motor brand" --- # Marketing Expert Was Allowed to Opine on Trademark Dilution Posted on March 18, 2026 by Expert Witness Profiler Plaintiffs Hyundai Motor Company and Hyundai Motor America, Inc. (collectively “Hyundai Motor” or “Plaintiffs”) are one of the largest automobile manufacturers worldwide, with vehicle sales in over 150 countries. Defendant Hyundai Technology is a manufacturer and seller of consumer electronics products including tablets, laptop computers/notebooks, desktop computers, monitors, digital storage, cell phones, and accessories. The Plaintiffs filed a trademark infringement suit against the Defendants for “using” the Hyundai name to sell their technology products. Defendants offered [Mark Keegan](https://expertwitnessprofiler.com/expert-witness/Mark-Keegan/1548509)‘s testimony to refute Plaintiffs’ allegations that Defendants’ conduct dilutes Plaintiffs’ HYUNDAI Mark. Plaintiffs filed a motion _in limine_ to exclude the testimony of Keegan. ## **Marketing Expert Witness** [Mark Thomas Keegan](https://expertwitnessprofiler.com/expert-witness/Mark-Keegan/1548509) has over 23 years of experience conducting consumer research, including being deposed and testifying at trial. Keegan earned his juris doctorate degree from Brooklyn Law School, has certifications in marketing knowledge and principles, and has completed post-graduate programs addressing market research processes. [Want to know more about the challenges Mark Keegan has faced? Get the full details with our Challenge Study report](https://expertwitnessprofiler.com/order/add?eId=1548509&pId=3). ## **Discussion by the Court** Keegan concluded that Plaintiffs’ allegations of dilution by tarnishment with respect to Defendant Hyundai Technology’s product user reviews do not “materially impact relevant consumer perceptions of Hyundai Motor, and as such, do not substantively impact the marketplace in which Hyundai Motor operates.” Keegan’s opinion relied on a study he conducted involving 850 participants identified as “likely purchasers of the Defendants’ products” based on their prior technology purchases. Keegan stated that he designed his survey in accordance with a combination of guiding principles, including survey research conducted for litigation purposes, relevant treatises in the field, including those from the American Bar Association, and industry leaders in market research. Plaintiffs argued that Keegan’s survey failed to employ well-established or reliable methodologies and did not rely on a representative sample because, among other things, 41.8% of respondents were age 61 or older. The Court, however, found that Keegan’s opinions are relevant as they address “consumer impressions of the Hyundai Motor brand,” which is a central issue to the underlying case. The arguments made by Plaintiffs are all issues to be decided by the jury based on credibility and weight. ## **Held** The Court denied Plaintiffs’ motion _in limine_ to exclude the testimony of Mark Keegan. ## **Key Takeaway** Expert opinion testimony is relevant if the knowledge underlying it has a valid connection to the pertinent inquiry. And it is reliable if the knowledge underlying it has a reliable basis in the knowledge and experience of the relevant discipline. ## **Case Details:** --- ## **You Might Also Like** ![Insurance Expert Not Allowed to Opine on the Cause of Death](https://ewp-blog.expertwitnessprofiler.org/wp-content/uploads/2026/04/blog-pic-640X480-2026-04-07T201226.004.jpg) [**Insurance Expert Not Allowed to Opine on the Cause of Death**](https://expertwitnessprofiler.com/marketing-expert-was-allowed-to-opine-on-trademark-dilution/insurance-expert-not-allowed-to-opine-on-the-cause-of-death)![Animal Behavior Expert Was Not Allowed to Opine on Drug Detection Dogs](https://ewp-blog.expertwitnessprofiler.org/wp-content/uploads/2026/04/blog-pic-640X480-2026-04-07T175803.497.jpg) [**Animal Behavior Expert Was Not Allowed to Opine on Drug Detection Dogs**](https://expertwitnessprofiler.com/marketing-expert-was-allowed-to-opine-on-trademark-dilution/animal-behavior-expert-was-not-allowed-to-opine-on-drug-detection-dogs)![Law Enforcement Expert Was Not Allowed to Opine on the Suspect's Flight](https://ewp-blog.expertwitnessprofiler.org/wp-content/uploads/2026/04/blog-pic-640X480-2026-04-07T131602.639.jpg) [**Law Enforcement Expert Was Not Allowed to Opine on the Suspect’s Flight**](https://expertwitnessprofiler.com/marketing-expert-was-allowed-to-opine-on-trademark-dilution/law-enforcement-expert-was-not-allowed-to-opine-on-the-suspects-flight)![Industrial Hygiene Expert's Testimony on Environmental Exposure Limited](https://ewp-blog.expertwitnessprofiler.org/wp-content/uploads/2026/04/blog-pic-640X480-2026-04-06T194531.503.jpg) [**Industrial Hygiene Expert’s Testimony on Environmental Exposure Limited**](https://expertwitnessprofiler.com/marketing-expert-was-allowed-to-opine-on-trademark-dilution/industrial-hygiene-experts-testimony-on-environmental-exposure-limited)![Psychology Expert's Testimony on Grooming Limited](https://ewp-blog.expertwitnessprofiler.org/wp-content/uploads/2026/04/blog-pic-640X480-2026-04-06T164223.328.jpg) [**Psychology Expert’s Testimony on Grooming Limited**](https://expertwitnessprofiler.com/marketing-expert-was-allowed-to-opine-on-trademark-dilution/psychology-experts-testimony-on-grooming-limited)