Customer Lifetime Value to CAC Ratio (LTV:CAC)

LTV meaning, Lifetime Value (LTV), is a performance indicator used to evaluate the total earnings generated by a customer throughout their entire tenure of using a mobile application. Historical data on user retention rates is often used to estimate the expected duration of user engagement. Having knowledge of what is LTV and the average LTV of your customers is crucial for executing successful marketing strategies. LTV in marketing for mobile apps is normally used to optimize revenue streams such as subscriptions, in-app advertising, and in-app purchases by determining the amount of money that can be spent on user acquisition while still being profitable.

The amount spent for each newly-acquired mobile app user over a given time period. Customer Acquisition Cost (CAC) for mobile apps refers to the cost that a business incurs to acquire a new user for their mobile application over a specific period of time. In other words, it is the amount of money spent to attract a user to download and install a mobile app on their device. Whether you are just embarking on your journey or navigating quite a while to create a successful mobile app, the Customer Acquisition Cost (CAC) must be at the forefront of your mind.

Return on Ad Spend (ROAS) measures the revenue generated for every dollar spent on advertising. It is calculated by dividing total revenue attributed to a campaign by the total ad spend on that campaign. A ROAS of 2.0 means the campaign generated $2 in revenue for every $1 spent. ROAS is the most widely used profitability metric in mobile user acquisition because it directly connects marketing investment to revenue outcomes. For subscription apps, ROAS calculations must account for the time lag between ad spend and revenue realization — a user acquired today may not generate their first payment for 7 days (if they start with a free trial) and may generate revenue over months or years of subscription renewals. This makes "Day 0 ROAS" (revenue from immediate purchases) an incomplete picture. Growth teams track ROAS at multiple horizons — Day 7, Day 30, Day 90, Day 365 — to understand the full return curve. Target ROAS thresholds depend heavily on a company's margin structure: apps routing payments through app store billing (with 15–30% commissions) need higher gross ROAS than apps processing through web checkout to achieve the same profitability.

Net Revenue Retention (NRR), also called Net Dollar Retention (NDR), measures the percentage of recurring revenue retained from existing customers over a given period, including the effects of upgrades, downgrades, and churn. An NRR of 100% means the business retains all of its existing revenue; above 100% means expansion from existing users exceeds losses from churn and downgrades. For subscription apps, NRR is a powerful indicator of product-market fit and monetization health. An app with 110% NRR is growing its revenue base by 10% from existing users alone, before any new customer acquisition — a strong signal that users find increasing value over time. NRR above 100% is often driven by users upgrading to higher-priced plans, purchasing add-ons, or re-subscribing after a lapse. Conversely, NRR below 100% indicates that the business must continuously acquire new subscribers just to maintain its current revenue level, putting pressure on user acquisition efficiency. Top-performing subscription businesses typically achieve NRR of 110–130%, and investors consider this metric one of the strongest predictors of long-term sustainable growth.

ARPU stands for Average Revenue per User, and it refers to the average amount of revenue an app generates from each active user. App growth teams that develop subscription or revenue-driven apps often include ARPU as a key performance indicator to measure their financial success. By calculating ARPU, you can determine the average amount of money you earn from each user. While ARPU takes into account the revenue earned from both paying and non-paying users, there is another similar metric used specifically for subscription-based apps. This metric is known as ARPPU (Average Revenue per Paying User), which only considers the revenue generated by users who have made a payment.