Reference
Product Management Glossary
Clear definitions of the terms that matter — written for founders and PMs who want precision, not jargon. Each definition is grounded in how the concept works in practice, not just in theory.
Activation Rate
The percentage of new users who complete the specific action that predicts long-term retention. Activation is not sign-up — it is the first moment a user experiences genuine value from the product. Improving activation rate is one of the highest-leverage early-stage product investments.
Read: Product analytics at early stage →Churn Rate
The percentage of customers or revenue lost in a given period. Customer churn counts the number of accounts lost. Revenue churn counts the revenue lost. The two can diverge significantly when large and small accounts churn at different rates, which is why revenue churn is often the more important number.
Read: How to reduce churn in early-stage B2B SaaS →GEO (Generative Engine Optimization)
The practice of optimizing a brand's presence so it appears in answers generated by AI engines like ChatGPT, Perplexity, Gemini, and Claude. Unlike SEO, which focuses on ranking pages in search results, GEO focuses on building the cross-platform authority signals that cause AI models to cite and recommend a brand.
Read: GEO vs SEO: what actually changes →GTM (Go-To-Market)
The strategy for how a product reaches its target customers. A GTM strategy defines the target customer, the value proposition, the channels used to reach them, the pricing model, and the sales motion. At early stage, most GTMs need to be revised significantly after the first 90 days of real customer contact.
Read: Your first GTM will be wrong →ICP (Ideal Customer Profile)
A detailed description of the type of company or individual most likely to get maximum value from a product, buy it with minimal friction, retain long-term, and expand usage over time. ICP is different from a persona — it describes the account, not the individual user. Getting ICP wrong is the most common cause of early-stage churn.
LTV (Lifetime Value)
The total revenue a business expects to earn from a single customer over the entire duration of the relationship. LTV divided by CAC (Customer Acquisition Cost) is one of the core SaaS health ratios. A healthy LTV:CAC ratio is typically 3:1 or higher, meaning the customer generates at least three times what it cost to acquire them.
MRR (Monthly Recurring Revenue)
The predictable revenue a SaaS business generates each month from active subscriptions. MRR is broken into new MRR (from new customers), expansion MRR (from upgrades and upsells), and churned MRR (from lost or downgraded accounts). Net new MRR is new MRR plus expansion MRR minus churned MRR.
North Star Metric
A single metric that captures the core value the product delivers to customers and predicts long-term revenue. A real North Star measures value delivered, not user presence. 'Daily active users' is not a North Star. 'Workflows completed without manual intervention' is closer. The discipline of a North Star is refusing to treat secondary metrics as equally important.
Read: How to find your North Star metric →NPS (Net Promoter Score)
A measure of customer loyalty based on a single question: how likely are you to recommend this product on a scale of 0 to 10? Promoters (9-10) minus Detractors (0-6) equals NPS. NPS is a useful directional signal but has significant limitations — it does not capture what would change the score, and it correlates weakly with retention in most B2B products.
NRR (Net Revenue Retention)
The percentage of revenue retained from an existing customer cohort over a period, including expansion from upgrades and upsells, minus revenue lost to churn and downgrades. NRR above 100% means the existing customer base is growing without adding new customers. VCs treat NRR as one of the most diagnostic SaaS metrics during diligence.
Read: What NRR tells you that churn rate does not →OKR (Objectives and Key Results)
A goal-setting framework where an Objective is a qualitative, ambitious goal and Key Results are the specific, measurable outcomes that define whether the objective was achieved. OKRs work best when they cascade from company level to team level and when Key Results measure outcomes, not output. Shipping 10 features is output. Improving Day-30 retention by 15% is an outcome.
PLG (Product-Led Growth)
A go-to-market strategy where the product itself is the primary driver of acquisition, conversion, and expansion — rather than sales or marketing. PLG requires a product that delivers genuine value through self-serve, a freemium or free trial model that creates real product experience, and viral or network loops that make the product spread naturally.
Read: What PLG actually means for early-stage B2B →PMF (Product-Market Fit)
The state in which a product satisfies a strong market demand — evidenced by high retention, organic growth, and users who would be genuinely disappointed if the product disappeared. PMF is not a feeling or a milestone. It is a threshold crossing that shows up in specific quantitative signals: Day-30 retention above category baseline, NRR approaching 100%, and organic inbound representing a growing share of new pipeline.
Read: How to know if you have product-market fit →PRD (Product Requirements Document)
A document that defines what a product or feature should do, who it is for, and how success will be measured. At early stage, a one-page PRD is almost always better than a comprehensive one — it forces clarity, is faster to write, and is more likely to be read by the engineering team.
Read: How to write a one-page PRD →RICE Scoring
A prioritization framework that scores product ideas by multiplying Reach (how many users affected per time period) by Impact (how much it moves the North Star, rated 0.25 to 3) by Confidence (certainty of estimates, as a percentage), then dividing by Effort (person-weeks). RICE creates a defensible, documented basis for prioritization conversations with stakeholders.
Read: How to prioritize when everything feels urgent →Retention
The percentage of users or customers who continue using a product over time. Retention is measured in cohorts — users who signed up in the same period — so you can see how different vintages of customers behave. Day-1, Day-7, and Day-30 retention form the standard early-stage tracking pattern. Each inflection point points to a different product problem.
Read: Why retention should come before acquisition →Roadmap
A plan that shows what a product team intends to build and in what sequence, typically organized by time horizon. A good roadmap communicates priorities and reasoning, not just a list of features. It is a living document — one that changes as new information comes in — not a commitment delivered to stakeholders and defended against revision.
Sprint
A fixed-length development cycle, typically one to two weeks, at the end of which a team ships a working increment of the product. Sprints create a predictable rhythm for planning, review, and retrospective. The sprint review is where the team demonstrates what was built and whether it achieved its intended outcome.
TAM (Total Addressable Market)
The total revenue opportunity available for a product if it achieved 100% market share. TAM is used in fundraising and strategy to establish the theoretical ceiling of a business. SAM (Serviceable Addressable Market) is the portion of TAM the product can realistically target. SOM (Serviceable Obtainable Market) is the share it can realistically capture.
Have a nuanced take on one of these terms?
Definitions are a starting point. The interesting part is how these concepts play out differently depending on the product, the stage, and the market. The Expert Perspectives publication is where practitioners publish those nuanced takes — contributions are open.