What is Digital Marketing?
Digital marketing uses online platforms, tools, and strategies to promote products, services, and brands. It includes paid search, SEO, social media, programmatic display, email, content, and analytics. Unlike traditional channels, performance is observable in impressions, clicks, conversions, and revenue, which enables evidence-based evaluation.
Because the work is technical and fast-moving, disputes often turn on configuration, measurement, and causation. Precise reading of the record is essential.
What Does Bill Hartzer Do as a Digital Marketing Expert Witness?
As an independent expert witness, Bill Hartzer provides analysis and testimony in matters involving online advertising, SEO, attribution, analytics, and related issues. He examines configurations, validates data integrity, and explains whether practices met accepted standards. His reports connect digital evidence to questions of causation, materiality, and damages.
Assignments may include ad account reviews, server log analysis, click fraud investigations, brand bidding disputes, or quantification of traffic and revenue impact after site or campaign changes. The objective is to offer clear, defensible explanations the court can rely on. For a deeper overview, see this primer on what a digital marketing expert witness is.
Overview
Bill Hartzer analyzes search, social, and programmatic channels along with GA4 and supporting systems. Findings are written in plain language, linked to exhibits, and reproducible. Counsel uses these findings to evaluate claims and prepare for deposition or trial.
Typical work includes assessing spend efficiency, intent coverage, audience quality, landing page effectiveness, and the chronology between changes and outcomes. He also highlights confounders that may explain observed results.
At a Glance
With more than two decades in digital marketing, Bill Hartzer brings both agency and in-house leadership experience. He is a qualified expert in federal and state cases for both plaintiff and defense.
- Hands-on with Google Ads, Microsoft Advertising, GA4, Search Console, Meta, LinkedIn, YouTube, and major DSPs
- Experience with expert reports, rebuttals, depositions, and trial testimony
- Focus on click fraud, traffic quality, advertising claims, and conversion integrity
Expert Services
Reports and Testimony
Bill Hartzer prepares expert reports and rebuttals that walk through sources, methods, findings, and conclusions. His testimony explains the evidence and the limits of what the record can support.
Digital Channel Analysis
He reviews search programs, paid social campaigns, SEO implementations, and programmatic placements. The analysis addresses standards of care, execution quality, and whether outcomes align with the available data.
Measurement and Causation
Hartzer validates GA4 property settings, tags, attribution logic, and funnel integrity, linking cause and effect where the record allows.
Risk, Abuse, and Compliance
He investigates invalid traffic, bot activity, conversion inflation, advertising claims, trademark bidding, and domain diversion patterns.
Common Matter Types
Bill Hartzer is often retained in cases involving disputes about performance, allegations of misleading conduct, or attribution of damages.
- False advertising and unfair competition
- Trademark and brand bidding conflicts in search
- Click fraud and invalid traffic
- Attribution and contribution disputes for leads, sales, or calls
- Online defamation and reputation impact
- E-commerce site performance and checkout issues
Methodology
Hartzer’s methodology emphasizes transparency and replication so that any party can follow the steps from evidence to opinion.
Credentials
Bill Hartzer has been a digital marketing consultant since the 1990s and is the founder of Hartzer Consulting. He has advised Fortune 500 companies, mid-market brands, and startups across industries. He is an industry speaker and published author on search, attribution, and online risk, and has qualified as an expert witness with extensive testimony experience.
Engagement Process
Engaging Bill Hartzer involves a conflict check, defining scope, evidence review, analysis, draft reporting, and finalized testimony.
FAQs
Which platforms are covered?
Hartzer works with Google Ads, Microsoft Ads, GA4, Search Console, Meta, LinkedIn, YouTube, major DSPs, and call-tracking systems.
Do you address damages?
He quantifies marketing impact such as lost traffic, leads, or revenue and coordinates with damages experts when broader economic modeling is required.
Do you work on both sides?
Yes. Bill Hartzer is retained by both plaintiff and defense. His role is independent and evidence-based.
Contact
Email: [email protected]
Please include case posture, jurisdictions, deadlines, and a short summary of the issues in dispute.
Disclosure: Bill Hartzer is not an attorney. His work focuses on digital marketing facts, analysis, and expert opinions for litigation.