Bill Hartzer · Digital Marketing & Legal Consulting
Digital Marketing Channels

Analytics, Attribution, and Measurement Expert Witness

Expert validation of marketing analytics, attribution models, conversion tracking, and ROI calculations for litigation where measurement accuracy is central to damages and liability.

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Why Analytics and Attribution Matter in Litigation

Nearly every digital marketing dispute ultimately involves questions of measurement. Whether the case concerns wasted advertising spend, lost revenue from traffic declines, or the performance of a marketing agency, the underlying claims depend on data. The accuracy, completeness, and proper interpretation of that data are often contested. Analytics and attribution are the systems that produce the numbers used to calculate damages, evaluate performance, and assign responsibility.

Bill Hartzer provides expert witness services focused on the measurement infrastructure that underlies digital marketing. His analysis validates whether the data being used in litigation is accurate, whether the analytical methods applied to that data are sound, and whether the conclusions drawn from marketing metrics are supported by the evidence.

Google Analytics Validation

Universal Analytics (UA) and Google Analytics 4 (GA4)

Google Analytics is the most widely used web analytics platform, and its data is frequently introduced as evidence in litigation. The transition from Universal Analytics to Google Analytics 4, completed in 2023-2024, introduced fundamental changes to how data is collected, processed, and reported. Bill evaluates Google Analytics implementations to determine whether tracking code was properly installed across all relevant pages, whether event tracking and goal configurations accurately captured the conversions and interactions that matter to the case, whether data collection was interrupted by technical errors, platform migrations, or configuration changes, whether the transition from UA to GA4 resulted in data gaps or inconsistencies, and whether the data being cited in litigation accurately represents actual website activity.

Understanding the technical differences between UA and GA4 is critical because the two platforms use different data models, different session definitions, and different attribution approaches. Comparing data across these platforms without accounting for these differences can produce misleading results.

Adobe Analytics and Other Platforms

While Google Analytics dominates the market, enterprise organizations frequently use Adobe Analytics, Mixpanel, Amplitude, or other analytics platforms. Each platform has its own data collection methodology, processing logic, and reporting capabilities. Bill's analysis accounts for the specific technical characteristics of whichever analytics platform is relevant to the case.

Conversion Tracking Validation

Conversion tracking is the mechanism by which marketing platforms record when an ad click or website visit leads to a desired action, such as a purchase, form submission, or phone call. Accurate conversion tracking is essential for evaluating marketing performance and calculating return on investment. Bill validates conversion tracking implementations across advertising platforms (Google Ads, Meta, Microsoft Advertising), analytics platforms, and third-party tracking systems. Common issues include misconfigured conversion events, duplicate conversion counting, broken tracking due to website changes, and discrepancies between platform-reported conversions and actual business transactions.

Measurement as the foundation of damages: In digital marketing litigation, damages calculations almost always depend on marketing measurement data. If the underlying measurement is inaccurate, the damages calculation built on that measurement is unreliable. Expert validation of analytics data is not a secondary concern; it is foundational to the credibility of the financial claims in the case.

Attribution Model Analysis

Attribution models determine how credit for conversions is assigned to the various marketing touchpoints a customer interacted with before converting. The choice of attribution model can dramatically affect how the value of different marketing channels is perceived. Bill analyzes attribution models used in litigation to assess their appropriateness and accuracy.

Each model produces different results from the same underlying data. In litigation, the choice of attribution model can significantly affect damages calculations, performance evaluations, and conclusions about which marketing activities drove business results. Bill evaluates whether the attribution model used is appropriate for the case, whether it was consistently applied, and how alternative models would affect the conclusions.

Marketing ROI Calculations

Return on investment calculations in digital marketing require accurate revenue attribution, proper cost accounting, and appropriate time frame selection. Bill reviews ROI analyses presented in litigation to verify that revenue figures are properly sourced and attributed, that all relevant costs are included (media spend, agency fees, technology costs), that the time frame used for the calculation is appropriate and not selectively chosen, and that the methodology is transparent and reproducible. Flawed ROI calculations are common in marketing disputes, and expert validation ensures that the financial analysis presented to the court is reliable.

Common Analytics Errors in Litigation

Bill frequently identifies analytics errors that affect the reliability of data used in legal proceedings. These include tracking gaps caused by missing or broken analytics code on key pages, data sampling in platforms that aggregate large datasets, which can introduce significant inaccuracies, filter misconfiguration that excludes or includes traffic incorrectly, cross-domain tracking failures that break user sessions across related websites, and timezone and date range errors that cause data to be misattributed to incorrect periods.

Tag Management and Implementation

Modern analytics implementations typically rely on tag management systems such as Google Tag Manager, Adobe Launch, or Tealium. Bill evaluates tag management configurations to determine whether tags were properly deployed, whether firing rules were correctly configured, and whether tag management changes introduced errors that affected data accuracy.

Cross-Device Tracking and Privacy

As users interact with marketing across multiple devices, tracking individual user journeys has become increasingly complex. Privacy regulations, browser restrictions on third-party cookies, and platform-level privacy changes (such as Apple's App Tracking Transparency) have further limited the accuracy of cross-device tracking. Bill evaluates how these limitations affect the reliability of marketing data in litigation, particularly when damages calculations depend on cross-device conversion attribution.

Why Measurement Is Increasingly Contested in Court

Digital marketing measurement is becoming more contested in litigation for several reasons: the deprecation of third-party cookies and other tracking mechanisms has reduced measurement accuracy, the complexity of modern marketing campaigns that span multiple channels and devices makes attribution inherently uncertain, opposing parties frequently rely on different data sources and methodologies that produce conflicting conclusions, and the financial stakes in marketing disputes have grown as businesses invest more heavily in digital channels. Expert analysis of measurement methodology is essential for helping courts evaluate the reliability of the quantitative evidence presented by both sides.

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Discuss an Analytics Case

Contact Bill Hartzer to discuss how analytics and attribution expert analysis can support your litigation.

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