How Do You Know if Your Product Features Are Going to Make an Impact?

There’s nothing more inefficient than building the wrong things, so how do you know if your product features are going to make an impact? I’ve covered the Pirate Metrics framework as a way to evaluate and prioritize features from a business perspective, but what we really want to know is the impact a feature makes from the user’s perspective. For that, we need a slightly different model.

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The HEART Framework

Google developed the HEART Framework as a way to set goals for and measure the impact of product features from the user’s perspective. HEART stands for:

  • Happiness
  • Engagement
  • Adoption
  • Retention
  • Task-Success


This is obviously a form of customer satisfaction. It’s a qualitative measure that attempts to answer the questions:

  • Does the feature delight the customer?
  • Is it frictionless?
  • Is it user-friendly?
  • Is it full of pleasing design elements?

Since it’s a qualitative metric, it’s best measured through customer interviews and satisfaction surveys.

It’s also important to have happiness as a primary design principle. Every new feature should be evaluated by its ability to delight the customer, rather than causing frustration.


Engagement is about how often users interact with the product or feature over a given period of time. Highly engaging features require little reinforcement, as users are eager to use it on a daily basis. You can measure engagement by the number of interactions as a proportion of the total user base in any given time period.

Engagement can be measured by the number of interactions over a given time period by the total number of active users. The common DAU/MAU ratio is an example of an engagement metric.


When referring to the product as a whole, adoption measures new user growth. In this case, it’s closely related to Acquisition in the Pirate Metrics model.

When looking at a specific feature, it’s how many of your active users are engaging with this feature. If you’ve created a valuable feature, positioned it properly in the application, and made your users aware of its existence and benefits, you should see a high percentage of your active users adopting new features.


Retention measures how long users stay active. It’s less about how active they are, only that they keep coming back over time.

If you are using a subscription model, you can simply measure how long they continue to pay for the subscription. Otherwise, you can measure the time between registration and their most recent activity.


This metric can be taken one of two ways. In the quantitative sense, you can simply measure whether or not your customers reach the end of the workflow successfully.

In reality, however, you want to determine whether or not the product or feature helped the user accomplish their goal. This is a much more impactful metric, but can only be captured through interviews and surveys.

How to Apply the HEART Framework

Make an Impact

To start, you want to set goals at a product level for each of these key impact metrics. This will allow you to set some guiding principles for design throughout your product. Then, for every new feature you evaluate, ask yourself “Will this feature support our design principles?”

Then, for each metric, ask yourself “How will we tell if we’re making an impact?” These are your signals.

Finally, determine the specific metrics you will track to measure impact. This may require some development work, but it’s a small investment to make in ensuring you’re building features that have an impact.


As product managers, it’s important for us to evaluate features by their impact on the bottom line, but as product designers, it’s more important that we focus on the impact on the user. The HEART Framework is a perfect compromise.

It keeps us tied to the performance metrics that matter, like engagement, growth, and retention, but it adds key elements of customer satisfaction and goal accomplishment, which can’t be bought with ads and are better indicators of long-term success.