BREAKING Firsthand closes $26M Series A led by Radical Ventures  •  AI Brand Agents meet consumers in moments of curiosity and intent  •  LAKEBED Your content, your data, your voice - kept under your control  •  FOUNDERS Built by the teams behind FreeWheel and AppNexus  •  HQ New York  /  ~53 people and hiring  •  BREAKING Firsthand closes $26M Series A led by Radical Ventures  •  AI Brand Agents meet consumers in moments of curiosity and intent  •  LAKEBED Your content, your data, your voice - kept under your control  •  FOUNDERS Built by the teams behind FreeWheel and AppNexus  •  HQ New York  /  ~53 people and hiring  • 
Company Dossier · Artificial Intelligence

Firsthand

AI-powered Brand Agents built for marketers and publishers - talking to your customers in real time, on your terms.

NEW YORK, USA   /   FOUNDED 2023   /   SERIES A · $26M

Firsthand brand illustration
Firsthand, photographed mid-thought. The brand-agent idea looks tidy here; the ad-tech status quo it is arguing with does not.
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There is a quiet meeting happening right now between a shopper and a question. Should I buy this? Is it right for me? Firsthand wants the brand itself to answer - in the moment, in its own voice, without a tech giant standing in the doorway collecting a toll.

Who They Are Now

A 53-person startup arguing with the entire ad-tech playbook

Firsthand is a New York company building AI agents that work for brands rather than around them. Its pitch is deceptively simple: give a marketer or a publisher their own AI representative - a "Brand Agent" - that can hold a real conversation with a consumer at the exact second curiosity strikes. Not a banner. Not a retargeting cookie chasing you across the internet. An agent that knows the product, speaks in the brand's voice, and remembers who owns the data when the conversation ends.

The company emerged from stealth in early 2024 and, by March 2025, had a $26 million Series A and a thesis loud enough to get noticed. It now runs lean - roughly 53 people - which is a polite way of saying it is small enough to still believe it can change how an entire industry talks to people.

"A lot of the stuff that's described as agents today is optimizing or automating marketing as it already exists. We think the opportunity is so much different and bigger than that."

- Jonathan Heller, Co-CEO & Co-Founder
The Problem They Saw

The middleman got too comfortable

For two decades, the deal was understood by everyone and loved by no one. Brands wanted to reach people. People lived inside platforms. The platforms sat in the middle, set the price, kept the data, and handed back a dashboard. It worked, in the way that paying rent works - reliably, and slightly against your interest.

Then generative AI arrived and most of the industry did the predictable thing: it bolted chatbots onto the old machine and called it innovation. Firsthand's founders looked at the same moment and saw something less convenient and more interesting. If AI can actually converse, then the conversation itself is the new channel - and whoever owns that conversation owns the relationship. The uncomfortable question underneath everything Firsthand builds: when AI becomes the way consumers ask questions, will brands speak for themselves, or will they rent a voice again?

"Firsthand turns AI into a direct channel, dismantling big tech's gatekeeper role."

- David Katz, Radical Ventures
The Founders' Bet

People who have done this before, doing it again

Jonathan Heller
Co-CEO & Co-Founder
Co-founder of FreeWheel, the video ad platform later acquired by Comcast.
Michael Rubenstein
Co-CEO & Co-Founder
Former president of AppNexus, the programmatic platform acquired by AT&T.
Wei Wei
Co-Founder
Completes a founding team whose past work runs through DoubleClick, AppNexus and FreeWheel.

This is the part skeptics should sit with. The people building Firsthand are not first-timers guessing at how advertising works. They helped build the plumbing that now powers ad businesses at Google, AT&T and Comcast. They are, in effect, arguing with the system they themselves wired - which is either the best possible credential or a fascinating midlife crisis. Probably both.

Lakebed™

Firsthand's quieter product is the one that makes the loud one possible. Lakebed is a data and knowledge rights management system for the AI era. It lets a brand's content and intellectual property be used by an AI agent without surrendering ownership - multiple parties can cooperate on data while everyone keeps the keys to their own.

It is named after the "data lake," except this one you are actually meant to own the bottom of.

The Product

Two pieces, one argument

Brand Agent Platform™

AI-powered brand representatives that engage consumers in moments of curiosity or intent, delivering real-time, adaptive experiences across owned properties and paid media placements.

For marketers: storytelling, lead-gen, and insights. For publishers: a new way to make money from readers who actually want to talk.

Lakebed™

The rights-management layer underneath. It governs what an agent knows, what it is allowed to say, and who owns the value created in the exchange.

The boring-sounding part that is, in fact, the whole point.

Put together, the platform lets a retailer help you find the right product, a bank walk you through a decision, or a travel company tailor a trip - each one as a conversation the brand controls end to end. The agents live where the consumer already is: on the company's own site, inside paid placements, and beyond.

The short, fast history of Firsthand

FOUR YEARS, ONE STUBBORN IDEA
2023
FoundedHeller, Rubenstein and Wei start the company around a single bet: AI is a new medium, not a new ad unit.
Feb 2024
Out of stealthFirsthand reveals itself as an AI agent platform for brands and publishers.
Mar 2025
$26M Series ARadical Ventures leads, with FirstMark, Aperiam, Crossbeam and a roster of adtech angels.
2025
Scaling upRunning campaigns for enterprise marketers and publishers, with stated plans to roughly double the team.
The Proof

The money showed up, and it brought receipts

The Series A is the cleanest evidence so far. Twenty-six million dollars, led by Radical Ventures - a returning investor, which matters, because returning investors have already seen the inside of the company and chose to come back. Alongside them: FirstMark Capital, Aperiam Ventures, and Michael Ovitz's Crossbeam Venture Partners. Yes, that Michael Ovitz - the Hollywood super-agent now writing checks for AI agents, a coincidence too neat to ignore.

The angel list reads like an adtech hall of fame: David Rosenblatt, Brian O'Kelley, and Bob Lord - people who built and sold the previous era's infrastructure and apparently like the look of the next one.

$26M
SERIES A
2023
FOUNDED
~53
EMPLOYEES
3
CO-FOUNDERS

Where the $26M came from

SERIES A INVESTOR LINEUP · MARCH 2025 · RELATIVE PROMINENCE, NOT EXACT ALLOCATION
Radical Ventures
Lead
FirstMark Capital
Part.
Aperiam Ventures
Part.
Crossbeam (Ovitz)
Part.
Angels x3
Rosenblatt+

Bars show each backer's role in the round, not dollar amounts - Firsthand has not disclosed the per-investor split. Angels: David Rosenblatt, Brian O'Kelley, Bob Lord.

The Mission

Give the voice back to whoever earned it

Strip away the product names and Firsthand is making one claim: the expertise a brand or a publisher has spent years building should reach people directly, in real time, without being filtered, ranked, or taxed by an intermediary. Firsthand calls AI "a new communication medium." The phrase sounds grand until you notice it is also a job description - the company is trying to make sure that when consumers start asking AI for advice, the answer can come from the source instead of a scraper.

Rubenstein frames the scale of it plainly, and he is not a man given to small claims.

"Brand Agents represent the biggest leap forward in advertising technology since programmatic advertising emerged."

- Michael Rubenstein, Co-CEO & Co-Founder
Why It Matters Tomorrow

The conversation is moving - the question is who owns it

Consumers are already learning to ask machines instead of search bars. That shift is not waiting for anyone's permission. The open question is whether the answers will belong to the businesses that created the knowledge, or to whoever happens to host the model. Firsthand is a bet on the former - that ownership of the conversation is worth building infrastructure to protect.

It is early, and the company is honest about being small. But the wager is clear, the team has built this kind of plumbing before, and the people who funded the last era are funding this one. Skeptics are right to wait for named customers and durable revenue. Optimists will note that "wait and see" is exactly what everyone said about programmatic, too.

Back to that quiet meeting between a shopper and a question. Today, more often than not, a platform answers. Firsthand is building toward a version where the brand does - in its own words, on its own terms, with the data still in its own hands. Whether the industry follows is unsettled. That Firsthand is going to make the argument is not.