A comprehensive guide to the key performance indicators that Y Combinator partners and top-tier B2B investors scrutinize, from retention and growth to unit economics, ensuring your startup demonstrates sustainable scale and product-market fit.
Get targeted exposure with custom position pinning and highlighted placement.
The backbone of predictable revenue for SaaS businesses, MRR provides a clear snapshot of monthly income from subscriptions. It serves as the primary baseline for measuring growth trends and projecting future cash flow in B2B models.
Measures revenue growth from existing customers, including upsells, cross-sells, and churn, without new logos. An NRR above 100% indicates strong product-market fit and expansion potential, which is a critical signal for Series A+ investors.
Calculates the total sales and marketing spend required to acquire a new paying customer. Tracking this metric ensures that your growth strategy is capital-efficient and helps determine the payback period for marketing investments.
Represents the number of months required to recover the cost of acquiring a customer through gross margin. Y Combinator prioritizes startups with a payback period under 12-18 months, indicating efficient capital usage and scalable growth engines.
The percentage of subscribers who cancel their subscriptions within a given period, including both logo churn and revenue churn. Low churn is essential for long-term sustainability, as it reflects customer satisfaction and the stickiness of your solution.
The average annual revenue generated per account, providing insight into your average deal size and sales cycle length. Understanding ACV helps founders tailor their sales motion and marketing messaging to the appropriate buyer persona.
Estimates the total gross profit a business can expect from a single customer account throughout their relationship. LTV is crucial for determining how much you can spend on acquisition while maintaining a healthy unit economics model.
A benchmark for evaluating the efficiency of your sales and marketing efforts, comparing customer lifetime value to acquisition cost. A ratio of 3:1 or higher is generally considered healthy, signaling that you are earning significantly more than you spend.
Measures customer loyalty and likelihood to recommend your product, serving as a leading indicator for future growth and churn. High NPS often correlates with organic word-of-mouth referrals, which can significantly lower effective CAC over time.
Tracks the percentage of new users or leads who successfully convert into paying customers within a specific timeframe. This metric helps identify friction points in the onboarding or sales process and validates the clarity of your value proposition.
Distinguishes between growth driven by user self-service and traditional outbound sales efforts. Investors need to know which motion dominates to assess scalability, as PLG often scales faster with lower marginal costs than enterprise sales.
Burn rate is the rate at which a company spends its cash reserves, while runway calculates how many months until cash runs out. Y Combinator expects founders to have a clear understanding of their financial runway to manage growth responsibly.
Logo churn counts the number of lost accounts, while revenue churn accounts for the value lost, including downgrades. Discrepancies between the two can reveal if you are losing small, non-strategic customers while retaining high-value enterprise accounts.
Revenue generated from existing customers through upgrades, additional seats, or new feature adoption. High expansion revenue indicates strong product stickiness and reduces reliance on continuous new customer acquisition for top-line growth.
The percentage of new users who experience a key 'aha!' moment or core feature usage within a defined period. High activation rates suggest effective onboarding and clear product value, which are prerequisites for reducing downstream churn.
The average time it takes to close a deal from initial contact to signed contract. Understanding this helps in forecasting revenue accurately and allocating appropriate resources to lead nurturing and follow-up activities.
The percentage of revenue remaining after subtracting the cost of goods sold (COGS), such as hosting and support. Healthy gross margins in SaaS typically exceed 70-80%, reflecting the scalability of the software model compared to hardware or services.
A benchmark stating that a SaaS company's growth rate plus its profit margin should exceed 40%. This metric helps investors balance the trade-off between aggressive growth investment and operational efficiency in mature startups.
The rate at which users signing up for a free trial become paying customers. This metric is vital for freemium or trial-based models, indicating the effectiveness of your pricing strategy and the perceived value of your premium features.
A composite metric combining usage data, support tickets, and engagement signals to predict churn risk. Proactively monitoring health scores allows teams to intervene with at-risk customers before they decide to leave, preserving revenue.