You are surrounded by market signals, but without the timing layer they are just data without direction. We help B2B SaaS teams turn that chaos into clarity, so they know exactly when to act, win, and grow.
Our work is not just about numbers or technology. It is about enabling real people to make a difference in their business by knowing who to focus on, when to act, and why it matters.
MarketSizer started out as TamCalc, a tool built by Niall O'Gorman in Dublin with one clear purpose: to help businesses calculate market opportunities.
At the time our focus was on top-down market sizing, but as we kept building we discovered something even more impactful. The challenge was not just sizing markets - it was uncovering actionable, competitive intelligence that teams could use to win, grow, and retain their ideal accounts.
What began as a straightforward market calculator evolved into what might be the largest and most accurate bottom-up subscription data set ever built, powered by more than 20 million subscription signals.
We realised the real challenge was not market sizing - it was knowing exactly when an account was ready to buy, renew, or expand. That is why MarketSizer is built to give GTM teams the timing edge they have never had before.
Niall O'Gorman starts TamCalc to help businesses calculate top-down market opportunities with less guesswork.
Initial backing from early supporters lets the team move from prototype to a working product.
TamCalc becomes MarketSizer, focused on bottom-up subscription data. The pre-seed round closes in May 2024.
Launched the MarketSizer App and shipped a Chrome Copilot prototype, supported by a bridge round to accelerate the platform build.
The Subscription Intelligence and Timing Intelligence platform goes live for B2B SaaS GTM teams.
Every claim we make is backed by real subscription data and inspectable signals - not guesses or vanity metrics.
Every score and signal comes with the evidence behind it. You should never have to trust a black box.
A hundred qualified opportunities beat ten thousand unqualified leads. We focus on signals you can actually act on.
We only win when our customers close more deals. That alignment shapes how we build, support, and price.
A small, remote-first crew across Europe, building subscription intelligence for GTM teams who want to act on evidence, not gut feel.
Chief Happiness Officer
15 minutes. No commitment. We'll show you the accounts in your market that are actively evaluating right now.
No credit card · Tailored to your ICP · Live data, not a slide deck
