Reading time: 7 min | TL;DR: Revenue grows when you consistently track MRR, Customer Churn Rate, Activation Rate, NPS and ARPA—and act fast when one of them turns red.

Why just five metrics?

When you’re building a B2B SaaS company, especially in the early stages, it’s tempting to measure everything. But the reality is: most of your growth and retention challenges come down to just a few key indicators.

In this post, you’ll learn the five essential customer success KPIs every early-stage SaaS team should track — and what to do if one of them looks bad.

📊 KPI #1: Monthly Recurring Revenue (MRR)

What is it?
Monthly Recurring Revenue (MRR) is the total predictable revenue you earn every month from active subscriptions. It’s your financial heartbeat as a SaaS business.

Why does it matter?
MRR tells you whether your business is actually growing month over month. It helps you forecast cash flow, track performance, and gives investors a fast sense of your momentum.

What if it’s not looking good?
If your MRR is flat or declining, you need to act fast. This might be a sign of customer churn, pricing problems, or poor expansion strategies.
 

Here’s what you can do:

• Review churned accounts and find the root cause.
• Introduce a limited-time upgrade offer to boost short-term revenue.
• Test annual plan incentives to lock in longer-term contracts.

How to track it:

Tools like ChartMogul or Baremetrics connect directly to Stripe* and show clean MRR dashboards.

For smaller startups: export your Stripe data weekly and track MRR manually in a Google Sheet.

*If you're not using Stripe, you'll have to manually calculate MRR. A bit more work, but doable.  

💔 KPI #2: Customer Churn Rate

What is it?
Customer Churn Rate is the percentage of customers who cancel or stop using your product over a specific period.

Why does it matter?
Losing customers is expensive. Churn reduces lifetime value, kills growth momentum, and makes every new acquisition less profitable.

What if it’s too high?
If your churn rate is consistently high (for example, over 5% per month), it’s likely a symptom of a deeper issue.

Here are a few fixes:

• Set up an exit survey to capture real cancellation reasons.
• Follow up with churned customers and offer to help them come back.
• Strengthen your onboarding process to keep users engaged from day one.

How to track it:

Use tools like Churnkey or Brightback to automate cancellations and offer recovery flows.

You can also calculate churn manually:

Formula: Customers lost ÷ Customers at the beginning of the period

⚡ KPI #3: Activation Rate

What is it?
Activation Rate is the percentage of new users who reach a meaningful first milestone in your product — often called the “aha moment.”

Why does it matter?
If people sign up but never experience value, they won’t stick around. A low activation rate means you're burning acquisition costs before even reaching the point where retention or monetization can happen.

What if it’s low?
Low activation is usually caused by friction in onboarding. 

Here’s how to fix it:

• Define one clear activation milestone (e.g. “Created first project” or “Uploaded first file”).
• Add guided product tours using tools like Userflow or Appcues.
• Send automated onboarding emails triggered by user behavior (not just time-based).

How to track it:

Use Mixpanel or Amplitude to set up funnels that track activation events.

For simple setups: log activation manually in your CRM or database and monitor it weekly.

😐 KPI #4: Net Promoter Score (NPS)

What is it?
Net Promoter Score (NPS) measures how likely your customers are to recommend your product to others, on a scale from 0 to 10. It’s calculated by subtracting the percentage of detractors (0–6) from promoters (9–10).

Why does it matter?
NPS is a leading indicator of loyalty, satisfaction, and potential word-of-mouth growth. It gives you both a number and direct customer feedback.

What if your NPS is negative or low?
This usually means customers are unhappy — even if they haven’t left yet.

Here’s what to try:

• Review detractor feedback for patterns (bugs, pricing, missing features).
• Reach out personally to a few detractors and ask how you can improve.
• Improve user experience with fast product wins or better communication.

How to track it:

Use tools like Delighted or Hotjar to send automated NPS surveys via email or in-app.

Keep a monthly record of scores and compare trends over time.

💸 KPI #5: Average Revenue Per Account (ARPA)

What is it?
Average Revenue Per Account (ARPA) is calculated by dividing your total recurring revenue by the number of active customers.

Why does it matter?
ARPA helps you understand your monetization power. If it’s rising, your upsells are working. If it’s falling, you might be underpricing — or attracting the wrong customers.

What if ARPA is too low?
 

Here’s how to increase it:

• Introduce upsell offers tied to usage milestones.
• Offer premium features to engaged accounts.
• Review your pricing model and consider tiered plans.

How to track it:

Stripe and HubSpot both allow basic ARPA tracking through reports.

In smaller teams, calculate it monthly in your financial tracker:
Formula: Monthly Recurring Revenue ÷ Number of active customers

🚀 Still feel like your KPIs are a bit of a mess?

If all of this still feels a bit overwhelming — that’s normal. Most early-stage SaaS founders are great at building product, but not trained in customer metrics.

That’s where we come in.

🚀 Book a free 30-minute strategy call

If you’re unsure where to start (or what to fix first) we’ll:
✅ Review your current setup
✅ Spot the biggest bottleneck
✅ Give you 1–2 practical next steps you can action immediately

No fluff. No obligation. Just clear, CS-driven growth advice.

👉 Book your free KPI strategy call – your MRR will thank you.

📘 KPI Acronym Glossary

MRR – Monthly Recurring Revenue

ARPA – Average Revenue Per Account

NPS – Net Promoter Score

KPI – Key Performance Indicator

SaaS – Software as a Service

CRM – Customer Relationship Management (e.g., HubSpot)