What an expert is for
An expert witness exists because a fact-finder — a judge, a jury, an arbitrator — is being asked to decide something that depends on how a technical system behaves, and nobody in the room can be expected to know. Whether a search engine would have shown one company's page for a competitor's brand name. Whether a domain name was transferred by its registrant or around them. Whether an analytics figure in a damages model measures what the model says it measures. Whether a post was published when the screenshot says it was.
Those are answerable questions, and the answer is either supported by preserved primary data or it is an opinion dressed as one. My work on the legal side is almost entirely the business of establishing which, and saying so in writing in terms that will survive a cross-examination designed to take it apart.
I want to state plainly what this page does not do. It names no case, no court, no docket, no deposition and no ruling. Expert engagements are routinely confidential, and a biography site that implies specific litigation without a citation is doing the same thing it would criticise an opposing expert for. What is described here is the practice: what the work involves, how it is done, what a retaining attorney should expect, and where I am likely to be of no use.
The six areas, and what separates them
SEO expert witness work turns on how search engines rank and why a set of results looked the way it did. The recurring difficulty is that there is no authoritative historical record of search rankings. Nobody can reconstruct a position that nobody observed at the time, and a rank-tracking export is a record of what one tool sampled from one location on the days it happened to run. An opinion that treats such an export as the ground truth of what a market saw is the easiest opinion in this field to dismantle, and I will not offer one.
Domain name expert witness work concerns registration, transfer, control and the record of who held a name and when. It is the most tractable area on this list, because the domain name system produces genuinely contemporaneous records: registrar logs, registry transaction histories, DNS zone changes, historical WHOIS. The evidence exists; the difficulty is obtaining it before retention periods expire and interpreting it without overstating what a record proves about a person as opposed to an account.
Internet expert witness is the broad category — how a website, a hosting arrangement, an advertising system or an email path actually worked at a point in time, and what can and cannot be established about it after the fact.
Social media expert witness work is dominated by one problem: authenticity and completeness of what was produced. A screenshot is an assertion about a screen. A platform data export is a far stronger artefact, and the difference between reviewing a party's export and reviewing their screenshots is usually the difference between an opinion and an impression.
Web analytics expert witness work is where damages models most often come apart, because analytics data is treated in litigation as if it were an accounting record and it is nothing of the kind. Consent banners, ad blockers, bot filtering, sampling, filter configurations and tagging changes all move the numbers, and a drop in sessions with no corresponding drop in orders is a tracking story rather than a business one.
Internet investigations is the underlying craft that the other five draw on: establishing attribution and history from registration records, DNS, hosting, archives and the connections between properties, and documenting the method so somebody else can run it again and get the same result.
Method: reproducible, logged, and hedged
Every review of data is a script rather than a session of clicking, so the analysis can be run again by anyone and produce the same output. Every request I make of counsel is logged with a date. Every conclusion is written with its evidentiary basis attached, and where the data will not support a conclusion, the report says that instead of reaching for one.
That last habit is the one I would defend hardest. The strongest thing an expert report can contain is a clearly marked limit: this is what the data shows, this is what it does not show, and here is what would have to be produced before the second question could be answered at all. An expert who never reaches a limit has not looked hard enough at their own material, and an opinion with no stated boundary invites the cross-examiner to find one for you.
The order of operations, and why it matters
A conflicts check comes before anything of substance. That is not a formality: hearing the facts of a matter before clearing conflicts can create a problem for the retaining party as much as for me. A useful first message from counsel states the type of matter, the jurisdiction, the procedural posture and the deadline, without case facts and without attachments.
After that comes the part attorneys most often want to skip, which is a discussion of what data would need to be preserved or produced before any opinion is possible. Preservation letters and discovery requests drafted with the technical shape of the evidence in mind are worth more than any amount of later analysis, because the analysis is bounded by what was preserved. Server logs roll over. Registrar records age out. Platform exports are only complete for the account that generated them.
When I am the wrong expert
If the question is one of law, I am not qualified to answer it and will say so. If the matter needs a forensic examination of a physical device, that is a different discipline with a different chain-of-custody practice. If the outcome depends on reconstructing rankings that were never recorded, no expert can honestly give you what you want, and being told that early is more valuable than being told it in a deposition.
How engagements are entered into
Through counsel, and through Hartzer Consulting rather than through this site. BillHartzer.net is a record: it publishes the practice, the background and the sources, and it deliberately has no intake form, no rates and no promise of availability. The sequence is a conflicts check, then scope and posture, then a written engagement — in that order, every time.