What Is SaaS?

What SaaS means in plain words

Before SaaS, a business bought software in a box or as a download, installed it on its own computers and paid again for the next version. With SaaS, you open a website, log in and the software is there. You rent access instead of owning a copy. Web-based email, online accounting tools and video meeting apps are everyday examples.

SaaS describes two things at once: how the software is delivered (online, hosted by the provider) and how it is paid for (a recurring fee). The second part is what makes it a distinct kind of business.

How a SaaS business works

A SaaS company builds one product and serves it to many customers. Customers pay monthly or yearly, often per user or by plan. Because the fee repeats, the company's income is the sum of everyone still subscribed. Growth comes from adding customers faster than you lose them.

A worked example

The numbers below are invented to show how the pieces fit. Say you build a booking tool for independent physiotherapists and charge $40 a month.

• You have 50 paying clinics, so MRR is 50 x $40 = $2,000.
• In one month, 2 clinics cancel. Monthly churn is 2 / 50 = 4%.
• You spent $1,200 on marketing that month and won 6 new clinics. CAC is $1,200 / 6 = $200.
• At $40 a month, each new clinic takes 5 months to pay back the $200 it cost to win, before any other costs.

The last line is the heart of SaaS. You pay for the customer now and earn the money back later. If customers leave before month five, you lose money on each one. If they stay for years, the business becomes very healthy. You can run your own figures in the MRR calculator and the CAC payback period calculator.

Why it matters for a first-time founder

You meet the term as soon as you consider a software idea. It is a popular model because income is predictable and one product can serve customers anywhere. The trade-offs are real, though: you have to build and maintain the product, income starts small, and you need enough runway to last while subscriptions build up.

The good news is that a SaaS idea can be tested cheaply. Interview the people who have the problem, then deliver the result by hand for a few of them, using spreadsheets and email, and charge for it. If nobody pays for the manual version, software will not fix that. The guides on how to validate a startup idea and how to build an MVP walk through this.

Fonda follows the same order: you talk to real customers in the Validate phase and get a Verdict of go, refine or pivot before you reach the MVP plan in the Launch phase. For a step-by-step path, see how to start a SaaS company.

Common mistakes

• Building for months before talking to a customer. The most expensive way to learn that nobody wants it.
• Watching sign-ups instead of churn. New customers hide the ones leaving, until growth slows.
• Pricing too low. A very low monthly fee means you need a huge number of customers to cover your costs. A freemium tier makes that harder still.
• Picking a tiny market. Check how many potential customers exist with the TAM SAM SOM calculator.
• Forgetting running costs. Hosting, support, payment fees and third-party services reduce what each subscription earns.