SaaS (Software as a Service) is cloud-based software billed on a recurring subscription, typically monthly or annually, where the vendor hosts, maintains, and updates the product so the customer never manages the underlying infrastructure.
At a glance
- Used across virtually every B2B category, from CRM and sales tools to data infrastructure.
- Pricing structures include per-seat, usage-based, and tiered flat-rate models.
- Health is measured by ARR, NRR, churn rate, and CAC payback period.
- A sale does not end at contract signature; retention determines whether the deal was profitable.
- GTM motion varies sharply by price point, not just by product category.
How does SaaS actually work in practice?
A company signs up, pays a fee tied to seats, usage, or features, and gets access through a browser or API. There is no installation and no one-time perpetual license. The vendor runs the infrastructure, ships updates, and handles security patches on their side.
Pricing models vary more than most people assume. Per-seat pricing is common in CRM and sales tools. Usage-based pricing dominates in data and infrastructure products. Tiered flat-rate plans show up often in early-stage tools trying to reduce friction in the buying process. Each model creates different revenue behavior and different buyer conversations.
Why does the SaaS model matter for B2B revenue teams?
The subscription model changes how you sell and how you measure success. A traditional software sale ended at the signature. A SaaS sale starts there.
Retention is revenue
If a customer churns after month six on a 12-month contract, you may have collected the cash, but your net revenue retention tells the real story. Companies with NRR above 120% grow without adding a single new logo. Companies with NRR below 90% lose ground no matter how many new deals they close.
Unit economics hinge on payback period
If it costs $18,000 to acquire a customer paying $1,500 per month, you need 12 months just to break even on acquisition cost before margin. Compressing that payback period or extending customer lifetime shifts the unit economics significantly.
GTM motion follows price point
A $49 per month self-serve tool runs a product-led motion with low-touch sales. A $120,000 ACV enterprise contract needs an account executive, multiple stakeholders, procurement, a security review, and a formal close process. Both are SaaS. Neither approach transfers cleanly to the other.
How is SaaS revenue actually measured?
Most B2B SaaS deals close on annual contracts, often with monthly payment options. A $24,000 ACV deal paid monthly is still annual recurring revenue, not monthly. That distinction matters when teams track ARR versus MRR.
The core metrics to watch are:
- ARR and MRR: the baseline of recurring revenue at any point in time.
- Churn rate: a 2% monthly churn rate means losing roughly 22% of the customer base each year.
- NRR: captures expansion and contraction, not just raw logo retention.
- CAC payback period: how long before acquisition cost is recovered from a customer’s payments.
- CLV: the total expected revenue from a customer over their full relationship with the product.
What are the most common SaaS mistakes and misconceptions?
- Treating ARR as cash flow. Deferred revenue, payment timing, and churn create gaps between the income statement and the bank account.
- Assuming low churn is good churn. At $2M ARR, a 2% monthly churn rate means roughly $440,000 leaving annually just to stay flat.
- Confusing product-market fit with distribution fit. A product can genuinely solve a problem and still fail because the GTM motion is wrong for the buyer, price point, or buying committee structure.
- Applying one GTM playbook across all price tiers. Self-serve motions and enterprise sales require fundamentally different teams, tools, and timelines.
How does SaaS connect to adjacent concepts?
SaaS metrics sit at the center of most B2B revenue conversations. ARR and churn rate show where the business stands today. CAC payback period and CLV show whether the growth is sustainable. ACV shapes how the sales team is structured and which GTM motions make sense at a given deal size.
Product-led growth is one specific GTM motion that fits lower-ACV SaaS products, where the product itself drives acquisition and expansion. Land and expand is another pattern common in SaaS, where a small initial contract grows through seat additions or feature upgrades over time.