SaaS vs Marketplace: Which Should You Build?

• Where the value lives: a SaaS application earns recurring revenue from its software features; a marketplace earns a percentage of transactions between buyers and sellers. Remove the network, and a marketplace collapses, but a SaaS product still delivers value to a single user.
• Cold start intensity: Launching a software as a service business means winning one type of user. You can sign up paying customers one at a time. A marketplace must attract supply and demand at the same time. Airbnb’s founders took photos of hosts’ homes to seed supply, and Deliveroo cold‑called restaurants.
• Revenue and investor expectations: SaaS revenue begins with your first subscription and is predictable; investors look at metrics like net revenue retention and payback period. Marketplaces earn nothing until real transactions happen at scale, and investors focus on gross merchandise value, take rate and liquidity.

Every founder has that moment: you’ve sketched an idea and see two plausible paths to bring it to market. On one path, you charge a recurring fee for a software as a service; on the other, you build a platform connecting two sides and take a slice of each transaction. Both look tempting, both have success stories, and both set your engineering and go‑to‑market roadmaps for the next two years. Getting the decision wrong can cost 18 months of runway and burn your team out.

This guide answers the specific question “Should I start a marketplace or SaaS?” It compares the models side by side, highlights the cold start problem, explains how investors weigh each model in 2026, and gives you a simple decision framework.

What is SaaS?

The SaaS definition is straightforward: software as a service means software hosted by its provider and accessed over the internet, paid for on a subscription basis. Instead of buying a licence once, a customer pays monthly or annually for ongoing access. The provider handles infrastructure, updates and maintenance. This model allows a single SaaS application to serve many tenants with one code base, a concept known as multi‑tenancy, which keeps costs low and ensures that updates reach all customers quickly.

Commercially, the defining characteristic is recurring revenue. Customers pay again and again for continued value, producing predictable, compounding cash flows. Popular SaaS services include Slack (collaboration), Figma (design), Xero (accounting), HubSpot (CRM) and Linear (issue tracking). Each runs in a browser or app and generates monthly recurring revenue (MRR) for its founders. If your idea charges users a recurring fee for access to software you build and host, whether through subscription, usage‑based billing or a hybrid plan, then it is a SaaS product.

What is a marketplace?

A marketplace is a platform that connects multiple independent sellers and buyers. Instead of owning inventory or building the core product itself, the marketplace provides a structure that helps transactions happen more easily, safely and at scale. A marketplace brings together sellers and buyers on a single platform, coordinates discovery and transactions, and typically earns revenue by taking a percentage of each completed transaction. Sellers list their goods or services, buyers browse and purchase, and the platform manages payments, feedback and dispute resolution.

Classic examples of marketplaces include Airbnb (hosts and guests), Etsy (sellers and buyers), Deliveroo (restaurants and consumers), Upwork (freelancers and clients) and Rightmove (property agents and purchasers). None of these companies creates the supply themselves; they aggregate and connect it. The marketplace’s value lies in its network: more sellers mean more selection for buyers, and more buyers increase the earning potential for sellers. Marketplaces do not buy or resell inventory; they inter­mediate transactions and earn money via take rate.

The core difference: where the value lives

At first glance, a SaaS product and a marketplace both involve building software and charging users, but their underlying economics diverge. The key difference is where the value resides:

Sources: Benchmarkit; a16z.

In short, SaaS is a software as a service model where revenue flows with each paying user, while marketplaces rely on network effects and transaction volume. This distinction shapes everything from your product roadmap to your funding strategy.

The cold start problem: the biggest practical difference

Launching a SaaS product means solving a one‑sided cold start: you need to attract paying users. You can build a waitlist, run ads, do outbound sales or offer free trials. One customer equals one unit of revenue. With good onboarding and a clear time‑to‑first‑value (the time from signup to the first moment a user realises value), you can convert that user into a subscriber quickly. SaaS founders should obsess over onboarding experiences, measuring the Time to First Value (TTFV) because it strongly predicts retention.

Marketplaces face a two‑sided cold start. You need supply and demand simultaneously. Supply won’t list without demand, and demand won’t join without supply. Network products suffer anti‑network effects at a small scale; users churn because there aren’t enough other users. Successful marketplaces solve this by manually seeding one side: Airbnb’s founders photographed hosts’ homes to kick‑start supply, Etsy’s founders recruited sellers at craft fairs and Deliveroo’s team cold‑called restaurants. Uber hired drivers directly for their first city launch. Each of these strategies required significant founder time and capital before liquidity existed.

If you cannot clearly articulate how you will solve this two‑sided cold start without burning more than £50k, the marketplace model is likely to stall. A SaaS business can find product‑market fit and generate revenue from a single user, whereas a marketplace must reach a critical mass of transactions before any revenue flows.

Revenue model comparison: how each one makes money

The way a business makes money informs its capital needs, cash flow and risk tolerance. Below is a comparison of revenue mechanics:

SaaS revenue is therefore predictable from month one. You know what you earned this month, you can model churn and expansion, and you can plan hiring accordingly. Marketplace revenue is lumpy and only arrives when real transactions occur. However, the ceiling for a marketplace that achieves liquidity in a large category can be enormous.

What investors think: SaaS vs marketplace at pre‑seed and seed

At the pre‑seed stage, investors primarily back founders, not metrics. Both models can raise capital with a compelling vision. But SaaS has a structural advantage: you can show a working product and one paying customer relatively cheaply. A pre‑seed raise for a marketplace requires investors to believe you can solve the cold start problem; this means your credibility and specific strategy matter enormously.

At the seed stage, the divergence widens. For software as a service companies, investors look at metrics like net revenue retention (NRR), customer acquisition cost (CAC) payback, the Magic Number (sales efficiency) and the rule of 40 (growth rate plus profitability). A seed‑stage SaaS company can show MRR growth, expansion revenue and early retention using these standardised metrics.

Marketplace investors, by contrast, focus on GMV (which is not revenue) and the take rate. They care about liquidity, the probability that supply meets demand, and look for GMV growth of 15–20% per month with liquidity above 60%. They scrutinise whether users transact repeatedly, whether supply quality is high and whether the network has built‑in mechanisms that discourage disintermediation. Investors evaluate marketplaces on three dimensions: whether supply and demand transact more efficiently over time, whether unit economics improve with scale, and whether growth is compounding through network effects rather than paid acquisition. With the venture market now rewarding efficiency over vanity GMV, marketplaces that demonstrate compounding liquidity and defensibility attract capital.

SaaS businesses are often more capital‑efficient; they can reach default alive (revenue covers costs) with less funding because they monetise early. Marketplaces usually need larger rounds to overcome the pre‑liquidity period. For founders bootstrapping or raising small seed rounds in the UK, SaaS technology is often the less risky path.

When each model wins: honest decision criteria

Some ideas intrinsically favour one model over the other. If your concept can deliver value to a single user on day one, and the core value lies in automation, analytics or workflow improvements, build a SaaS application. If the value only emerges when two sides interact, buyers and sellers, hosts and guests, freelancers and clients, and you have a clear plan to seed both sides, a marketplace may be right. Below are straightforward criteria:

Build SaaS when:

• The value is in the software, not the network. Removing other users does not break the product.
• One type of customer has a clear problem and will pay to solve it.
• You can demonstrate value to a single user without any network effects.
• You want predictable recurring revenue from day one.
• You have a small team or limited runway and need capital efficiency.
• You can validate demand with a prototype before heavy investment.

Build a marketplace when:

• The value is in connecting two distinct sides; neither side is useful without the other.
• You have a credible, specific plan to solve the cold start problem for both supply and demand (for example, manually onboarding the first 50 suppliers and 100 buyers).
• You have access to enough capital to sustain 12–24 months of pre‑liquidity operations.
• You can build a defensible supply monopoly in a niche or geography before expanding; dense networks outperform broad, shallow ones.
• You possess industry experience and relationships on the supply side.
• You’re prepared for GMV‑based revenue that depends on transaction volume.

Beware the hybrid trap: building a marketplace and a SaaS product simultaneously almost always results in doing both badly. Validate one model to product‑market fit first, then add the second dimension once the first is humming.

Three questions to make the decision

If you still feel unsure, answer these three questions. They form a quick decision framework you can run through in five minutes:

1. Where does the value live? If you removed all other users tomorrow, would your product still be useful to a single customer? If yes, you’re likely building SaaS. If no, and the value only exists when two sides interact, you’re building a marketplace.
2. Can you seed one side manually? If you can sign up 20 suppliers or 50 buyers manually before writing any code, a marketplace may be viable. If you cannot imagine how to get either side without a fully working platform, the cold start problem will probably kill it.
3. Do you need revenue within six months? If you must generate revenue quickly or are bootstrapping, build a SaaS product. If you have 18–24 months of runway and a strong network in the relevant industry, you can consider a marketplace.

If, after answering these questions, you decide that a SaaS system is the right path, the next step is building it. That’s where choosing the right partner matters.

Why Rattlesnake?

Many studios will offer to “build your SaaS” by throwing engineers at the problem. At Rattlesnake, we believe the formula for a commercially viable product is a blend of design, development and marketing expertise. We’re a boutique studio, and our founders are personally involved in every project.

You’ll work directly with us, not through layers of account managers. That means your idea receives the attention it deserves at every stage, from ideation to launch and growth. We don’t hire anonymous freelancers; we immerse ourselves in your market, share responsibility for design, functionality and go‑to‑market, and apply honesty when advising whether SaaS or marketplace is right for you.

Not sure which direction is right for your idea? Book a quick call with the Rattlesnake team. We will give you a clear next step.