What is Tertium Quid?

Tertium Quid is a revenue-split product partnership operated by Upper Eight AB and led by its co-founder Dennis Elmersson. Upper Eight builds digital products end-to-end for senior domain experts with an existing audience. The partner brings expertise and audience; Upper Eight brings the build. Revenue is split 50/50 from day one with no upfront cost from the partner.

How is revenue split in Tertium Quid?

50/50 from the start, clean, with no tiers. Paid monthly via Stripe Connect, automatic and transparent.

Who owns the intellectual property in Tertium Quid?

Dennis Elmersson owns the code, infrastructure, and product brand. The partner owns their underlying expertise and grants a license to use it in the product. Clean separation.

How does either side exit a Tertium Quid partnership?

Either side can leave with three months' notice. A buyout option is available, with the terms set in the contract. No lock-in.

Who is Tertium Quid for?

Senior practitioners with ten or more years of recognised practice in their field, an audience that already trusts them, and a clear sense of what their clients would pay for. Not for founders testing a new business idea, and not for early-career consultants still building a name.

What does the Tertium Quid contract look like?

A short term sheet up front, then a proper contract before we start building. Nothing hidden, nothing rushed.

Tertium Quid: A revenue-split product partnership

The model

Two people, a few weeks of focused work, a real product launched to your audience.

You bring the expertise and the door.

Ten or more years of recognised practice in your field. A reputation and an audience that already trust you. Two or three weeks of focused input to shape the product. A clear sense of what your clients would pay for alongside your work.

I bring the build, end to end.

Full product development: web, app, plugin, whatever fits the audience. Branding, design, technical setup, hosting, payments, ongoing maintenance. All build and infrastructure costs covered. Concept to launch within weeks, AI-accelerated.

AI does the rest.

What used to need a studio of ten now ships with just the two of us. That’s the whole reason a partnership like this works at all. A few years ago, it wouldn’t have.

The proof

02.1 Dennis GEO Already running

Running, built alone, on my own expertise.

Dennis GEO is a WordPress plugin I built and sell. It helps a site get found and quoted by AI assistants the way sites once optimised for Google: clean structure, machine-readable answers, the things language models actually read. Free to install; a paid option writes the optimised content for you. It runs on its own and pays its own way.

It works because I have years of web-development experience and know exactly what agencies and their clients need. That’s the same dynamic I’m looking to repeat with you, only this time your expertise is the wedge, and the product reaches your audience instead of mine.

Dennis GEO: WordPress plugin for AI search visibility

dennisgeo.com

The deal

Revenue, ownership, exit: agreed up front, in writing.

Revenue split: 50 / 50 from the start: clean, no tiers. Paid monthly via Stripe Connect: automatic and transparent.
Costs: I carry all build, hosting, and maintenance costs. No upfront fee from you.
IP: I own the code, infrastructure, and product brand. You own your underlying expertise and grant a license to use it in the product. Clean separation.
Exit: Either side can leave with three months’ notice. Buyout option, with the terms set in the contract. No lock-in.
Contract: A short term sheet up front, then a proper contract before we start building. Nothing hidden, nothing rushed.

The fit

This works best with partners who already have all three.

A decade-plus of recognised practice.

You’ve been in your field long enough that your name carries weight in it: clients come to you because of who you are, not because they found you in a search.

An audience that already trusts you.

A client base, a list, a network, an active professional presence. Not a brand to build from scratch: an existing channel a new product can ride on from day one.

A clear sense of the next purchase.

You know what your clients pay you for. You also have an instinct for what they would happily pay for alongside, if it existed in the right form.

Said directly

This isn’t for founders testing a new business idea, and it isn’t for early-career consultants still building a name. A revenue-split partnership only works if there’s already proven expertise and an existing audience to launch to: that’s structural, not a value judgement. I’d rather say it plainly than waste a conversation.

Next step

If this sounds like the kind of partnership you’d run, write to me. A 30-minute call is the next step, nothing more committed than that.

dennis@elmersson.ai

+34 638 212 780

I take on a small number of partnerships at any time. The quality of fit matters more than the speed.

No form. No calendar link. No chatbot. Email or phone reaches me directly: same as the front page.