A software as a service (SaaS) business sells ongoing access to a piece of software, billed monthly or annually. It's the model that commands the highest valuation multiples of anything on this list, for a specific reason: subscription revenue is predictable in a way that ad income, affiliate commissions and one-off product sales simply aren't. That predictability is real, but it comes with a real requirement most first-time buyers underweight, which is technical fluency somewhere in the operation.
What running one actually looks like week to week
Even a small SaaS product you didn't build requires handling customer support tickets, prioritizing and shipping bug fixes or small improvements (or managing a developer who does), and watching churn, the rate at which customers cancel, closely. Churn is the single number that most determines whether the business grows or shrinks, more than new sign-ups do in many small SaaS products. You're also watching monthly recurring revenue (MRR) trends, failed payment recovery (dunning), and usually running some amount of ongoing marketing to keep new sign-ups flowing in.
Typical profit margins
| Line item | Typical range | What drives it |
|---|---|---|
| Gross margin | 70% to 90% | Hosting and payment processing costs, which barely grow per additional customer once the product is built |
| Net margin (profitable, bootstrapped) | 25% to 40% | After support, product development, and marketing, before reinvestment |
| Net margin (venture-backed, growth stage) | Often negative | Deliberately spending ahead of revenue to capture market share, a different objective than a solo buyer's |
| Monthly churn (healthy small-business SaaS) | 2% to 5% | Below 3% monthly is generally considered strong for sub-$1 million annual recurring revenue (ARR) products |
| Typical sale multiple | 2 to 4x ARR (sub-$1 million ARR) | Based on marketplace data from platforms like Acquire.com and MicroAcquire. Multiples rise with size, growth rate and how low churn is. |
The "Rule of 40," a common SaaS health benchmark, says growth rate plus profit margin should add up to 40 or more. A SaaS product growing at 10% a year needs roughly a 30% margin to clear that bar. A shrinking product needs an even higher margin to compensate, which is exactly the kind of business a buyer should be able to spot from the numbers before ever talking to the seller.
Pros
- Recurring, predictable revenue that's visible weeks or months in advance, unlike ad-based or transactional income.
- Very high gross margins because the marginal cost of serving one more customer is close to zero once the product exists.
- Sticky customer relationships. Switching software is genuinely annoying for a customer, which naturally suppresses churn relative to, say, an e-commerce purchase.
- Commands the highest valuation multiples of any model here, which matters just as much on the way out as on the way in.
Cons
- Requires ongoing technical maintenance. Software breaks, security patches are needed, and hosting infrastructure needs monitoring, none of which is optional.
- Churn compounds against you. A product losing 5% of revenue a month needs to replace that just to stand still, before it can grow at all.
- Customer support expectations are high and immediate. Users expect a working product now, not a next-business-day response.
- A non-technical buyer without a reliable technical hire or contractor in place is taking on real operational risk, since a single serious bug or outage can trigger a wave of cancellations.
Skills and time required
You don't need to be able to write the code yourself, but you need enough technical fluency to evaluate a developer's work, understand what a bug report actually means, and make informed product decisions, or a trusted technical hire or contractor who can. Customer support and basic product management (deciding what to build next based on what customers actually ask for) are constant, ongoing demands. Some comfort reading MRR, churn and cohort retention data is essential, since these numbers tell you about the health of the business faster than revenue alone does.
What to check before buying one
Ask for a cohort retention chart, not just a churn percentage. A stated "3% monthly churn" can hide a business where new cohorts churn fast and only a legacy cohort is stable, a very different risk profile than uniform low churn across all customers. Confirm who currently handles the technical side (the seller, a contractor, an agency) and whether that person or relationship transfers with the sale. Check for customer concentration. A B2B SaaS product where one customer is 20% of revenue carries real key-account risk that a simple MRR chart won't show.
Real examples: Basecamp has run as a self-funded, subscription-billed project management tool for years without outside investors, prioritizing profitability over growth-at-all-costs. Ahrefs built a subscription SEO-tools business the same way, growing through organic marketing and product-led growth rather than a large outbound sales team, while staying profitable and bootstrapped.
Next: marketplaces run on connecting two sides of a transaction, a different balancing act than serving a single type of customer.