Product-led growth (PLG) is a go-to-market model where the product itself is the primary driver of customer acquisition, activation, expansion, and retention. In a PLG model, users discover the product through free trials or freemium tiers, experience value on their own terms, and convert to paid plans based on product usage rather than sales outreach. Slack, Notion, Calendly, and Figma are canonical examples.
Measuring PLG requires a different set of metrics than traditional sales-led growth. Because acquisition and conversion happen primarily in the product, the data that matters most is product engagement data, not pipeline data. The metrics that follow are the core set for understanding and improving a PLG engine.
Activation Rate
Activation rate is the percentage of new signups who reach a defined first-value milestone within a specified time window. In a PLG model, activation is the most critical early-funnel metric because it predicts whether a user will eventually convert to paid.
The activation milestone should correlate empirically with long-term retention — not onboarding completion, but the first moment the user could plausibly think “this product does what I needed.” For a project management tool, that might be creating and assigning the first task. For an attribution tool, connecting the first data source and viewing a meaningful report.
Improving activation rate is one of the highest-leverage investments in PLG because the improvement compounds downstream: more activated users produce more trials, more trials produce more conversions, and more conversions produce more revenue from the same acquisition spend.
Time to Value (TTV)
Time to value measures how long it takes a new user to reach the activation milestone. It is the velocity version of activation rate: activation rate tells you what percentage of users make it; TTV tells you how quickly.
In PLG products where trial periods are limited (a 14-day free trial, a freemium tier with usage caps), TTV directly affects conversion likelihood. A user who reaches the activation milestone on day 2 of a 14-day trial has significantly more runway to experience deeper value and encounter the reasons to upgrade. A user who reaches the milestone on day 12 barely has time to convert before the trial ends.
TTV is measured as the median or average time from account creation to activation milestone, typically in hours or days. Reducing TTV requires removing friction from the critical path to activation: shorter setup flows, better defaults, smarter empty states, and more direct guidance to the first value action.
Free-to-Paid Conversion Rate
Free-to-paid conversion rate is the percentage of free users (trial or freemium) who convert to a paid plan within a defined period. It is the core revenue-generating metric in a PLG model.
Benchmarks vary significantly by model and market:
- Freemium B2B SaaS: 2-5% is typical; best-in-class is 8-15%
- Free trial B2B SaaS (with credit card): 25-40%
- Free trial B2B SaaS (no credit card required): 10-20%
- Consumer apps: 1-3% is common
Conversion rate should be tracked by cohort (month of signup), because conversion curves are not instantaneous — some users convert immediately at trial end, while others convert 6-12 months after initial signup when their usage grows into paid feature requirements. Aggregate conversion rates without cohort tracking understate eventual conversion from recent cohorts and overstate it from older ones.
Product Qualified Lead (PQL) Rate
Product qualified leads (PQLs) are free users who have demonstrated usage patterns associated with high conversion likelihood. Unlike marketing qualified leads (MQLs, which are based on demographic fit and marketing engagement), PQLs are identified based on product behavior.
Common PQL signals:
- Reaching the activation milestone
- Inviting team members to the product
- Returning to the product 5+ times in the first 14 days
- Using a feature that is only available on paid tiers (or hitting a usage limit)
- Company size or role signals that indicate a budget holder
PQL rate is the percentage of new signups who become PQLs within a defined window. When sales teams exist in a PLG model, they focus on PQLs rather than all free users — the PQL filter concentrates outreach on users who have already demonstrated intent through product behavior.
Expansion Revenue Rate
In PLG companies, expansion revenue (additional revenue from existing paying customers through seat additions, plan upgrades, or usage-based growth) often becomes the primary growth driver as the company matures. The economics of expansion revenue are favorable: no acquisition cost, short sales cycle, high margin.
Expansion revenue rate is typically measured as a percentage of starting MRR/ARR: if a cohort of customers generated $100,000 ARR in year one and $130,000 ARR in year two without adding new customers, the expansion rate is 30%.
The classic PLG expansion driver is usage-based pricing: as a user or team uses more seats, more API calls, or more storage, the account naturally expands without requiring a renegotiation or a new sales motion. Companies like Snowflake, Twilio, and Stripe have built large revenue bases on usage-based expansion mechanics.
Net Revenue Retention (NRR)
Net revenue retention measures the percentage of ARR from a cohort of existing customers retained and grown over a period (typically 12 months), including expansion and net of churn and contraction. An NRR above 100% means existing customers are growing faster than churning — the installed base is growing on its own without any new customer acquisition.
NRR is the north-star retention metric for PLG companies because it captures both the retention floor (logo retention) and the expansion ceiling in a single number. Best-in-class PLG companies sustain NRR of 120-140%+, which means that even if they acquired zero new customers, revenue would grow 20-40% annually from the existing base.
Daily Active Users / Monthly Active Users (DAU/MAU)
The DAU/MAU ratio (also called the “stickiness” ratio) measures what percentage of monthly active users are engaging with the product on any given day. A ratio of 50% means that half of everyone who used the product this month used it today — indicating high habitual engagement.
Stickiness benchmarks:
- Below 10%: low stickiness, product is not central to user workflow
- 10-20%: moderate stickiness
- 20-50%: good to excellent stickiness (consumer apps in this range are strong performers)
- 50%+: exceptional stickiness (messaging apps, communication tools)
DAU/MAU is most relevant for products where daily or near-daily usage is expected (communication tools, project management, collaboration). For products designed for weekly or monthly use (annual tax software, quarterly reporting tools), DAU/MAU is a less meaningful benchmark than WAU/MAU or session depth metrics.
Virality: Viral Coefficient and Viral Cycle Time
Many PLG products grow through built-in virality: users invite colleagues, share outputs with external parties, or create content that attracts new users. The viral coefficient measures how many new users each existing user generates on average. A viral coefficient above 1 means the user base grows exponentially from virality alone (unsustainable in practice, but a meaningful target for product-led viral growth).
Viral cycle time is the average time between a user joining and their invitees joining. A short viral cycle time (days rather than weeks) compounds viral growth faster.
For PLG products with network effects (Slack, Notion, Figma), viral mechanics are a primary growth driver. Tracking invitation rates, shared link conversion, and invitee activation rates allows product teams to optimize the viral loop rather than treating it as a passive byproduct.
Feature Adoption Rate
Feature adoption rate measures the percentage of active users who have used a specific feature within a given period. It is a diagnostic metric for identifying which features are driving engagement and which are invisible to most users.
Features with low adoption are either: not discoverable (a UI or onboarding problem), not relevant to most users (a product-market fit problem), or not providing enough value to be worth the effort to learn (a feature quality problem). Tracking adoption by feature and by user cohort helps product teams prioritize where to invest in feature improvement vs. feature discovery improvements.
Putting PLG Metrics Together
The PLG metrics framework can be organized as a funnel:
- Signup: total new accounts created
- Activation: percentage who reach first-value milestone (activation rate) and how quickly (TTV)
- PQL: percentage who show conversion-predictive behavior (PQL rate)
- Conversion: percentage of free users who pay (free-to-paid conversion rate)
- Retention: revenue retained and grown from paying customers (NRR, logo retention)
- Expansion: additional revenue from existing customers (expansion rate)
- Virality: new users generated by existing users (viral coefficient)
No single PLG company optimizes all of these simultaneously. The highest-leverage metrics depend on stage: early-stage companies prioritize activation and free-to-paid conversion; mature companies increasingly optimize NRR and expansion. The value of tracking the full set is that it reveals which stage of the user journey is the binding constraint on growth — and makes it possible to concentrate improvement effort where it will have the largest downstream effect.