Product metric frameworks: AARRR vs HEART vs North Star
Simply put, product metrics are the quantifiable data points that give you insights into how your product is performing.
They can tell you whether your users are finding value, and if they’re sticking around or drifting away. Metrics tell a story. The kind of story that can drive change, spark growth, and help you see where things need attention.
They’re an effective tool for sharpening focus, alignment, and accountability. They can help you spot problems before they snowball, make decisions based on data, and experiment with confidence.
While many teams and organisations would likely not refute the benefits of being more data-driven (or ‘data-informed’ as Ant Murphy puts it) – putting this into practice is often more complicated. What should and shouldn’t we be measuring? How do we connect our product’s functionality and experience to our business level metrics? What makes a good metric?
That’s where a solid product metric framework can help. And while there are a bunch of great frameworks out there, today we’re going to focus on three of the most popular: AARRR (Pirate Metrics), HEART, and the North Star Framework.
In this article we break each one down, see what they’re good for and what they’re not so good for, to help you choose the best one for your team or organisation.
AARRR: The Pirate Metrics Framework
If you’ve been around product teams for a while, you’ve probably heard of AARRR, or Pirate Metrics as they’re often referred to. Created by Dave McClure, the framework breaks down the customer journey into five key stages:
- Acquisition - How you get users to your product.
- Activation - How you get users to make that first key interaction (like signing up, or completing their first task).
- Retention - How you get users to come back, again and again.
- Revenue - How you monetise your proposition and keep those revenues growing.
- Referral - How you get your users to tell their friends, bringing in new customers.
AARRR is great because it’s simple, intuitive, and directly tied to your user journey. It’s also handy for spotting friction points – when your users are getting stuck or dropping off – and giving your team something concrete to focus on.
Pirate Metrics also provide a straightforward structure for aligning your product metrics with business metrics. Key business metrics like Annual Recurring Revenue (ARR) and user base growth can either be a parent of the relevant stage, or they can be a top-level metric within it.
If you want a more detailed dive into how to use AARRR effectively, check out our own Dave Baines’s fantastic article: AARRR: Getting the most out of Pirate Metrics.
Good for: Startups and growth teams who want a simple, actionable framework that follows the entire customer journey.
Not so good for: Products where user satisfaction or qualitative user experience is critical but difficult to quantify.
HEART: The User Happiness Framework
The HEART framework was created by Google and was initially designed for measuring user experience, but it’s equally useful to apply at a whole product level. It’s made up of five areas that help you evaluate how happy your users are:
- Happiness - Satisfaction, user attitudes, NPS (Net Promoter Score).
- Engagement - How actively users are interacting with your product.
- Adoption - How many new users adopt a feature over time.
- Retention - The percentage of users who return after their first use.
- Task success - How efficiently users are able to achieve their goals.
While there’s a fair amount of overlap with Pirate Metrics, there is more of an emphasis on the user experience.
It’s designed to help you understand what’s making users smile (or frown) when they interact with your product. It’s great for measuring progress at a feature level or focusing on making improvements in specific parts of the experience.
Good for: Teams focused on improving UX and tracking the success of features at a granular level.
Not so good for: Teams focused on overall growth metrics or business-level outcomes.
The North Star Framework
The North Star Framework focuses on identifying a single guiding metric that represents your product’s value to customers. Created by Amplitude, the idea is that if your North Star Metric goes up, your business is creating sustainable growth. Behind that guiding metric are supporting inputs – smaller metrics that contribute to moving the North Star.
For instance, a music streaming app might use ‘time spent listening’ as their North Star Metric, with supporting inputs like ‘number of daily active users’ or ‘number of playlists created’.
The North Star Framework works well when your team needs a simple, shared goal. It helps to align everyone’s efforts around one vision, which can be powerful for focus. But it’s not always easy to pick the right North Star – you want something that captures value to your users, rather than just your revenue numbers.
Good for: Teams looking to align on a single vision, especially at scale.
Not so good for: Startups who need to experiment quickly or products with lots of competing priorities that can’t be captured in one number.
Which metrics framework is right for you?
Choosing a metrics framework can be tricky, and there’s no one-size-fits-all. AARRR is great for growing and scaling, HEART is fantastic for improving user experience, and the North Star Framework works wonders for rallying the whole team around a common goal.
Here’s a summary:
- If you’re starting out, focus on AARRR to get an understanding of the full customer journey.
- If you’re diving into user experience, HEART can give you the metrics you need.
- If your team needs a single focal point, the North Star will help.
Product metrics are powerful, but they’re just a tool. The real magic happens when your team’s decisions are driven by what those metrics are telling you. So, get your framework in place, start tracking, and use the insights to drive better decisions, one small improvement at a time.
