AARRR Pirate Metrics Framework, also known as the Pirate Metrics Model, is a framework used to measure the success of a business or product. The framework is commonly used in startup environments, where growth and customer acquisition are critical factors for success.

The five metrics represented by the acronym AARRR are:

1. Acquisition: Acquisition refers to the number of new customers or users that a business or product has acquired within a specific period of time. This can include metrics such as website traffic, social media followers, or app downloads.
   
   
2. Activation: Activation refers to the percentage of new customers or users that have taken a specific action that demonstrates engagement with the product or service. This might include signing up for a trial, creating an account, or completing an onboarding process.
   
   
3. Retention: Retention refers to the rate at which customers or users continue to use the product or service over time. This is an important metric, as retaining customers is generally more cost-effective than acquiring new ones.
   
   
4. Revenue: Revenue refers to the amount of money generated by the product or service, either through direct sales or other revenue streams such as advertising or subscriptions.
   
   
5. Referral: Referral refers to the number of customers or users that have referred others to the product or service. This metric can be an indicator of customer satisfaction and can help drive growth through word-of-mouth marketing.
   

By using the Pirate Metrics Framework, businesses can identify areas where they need to improve and focus on specific metrics to drive growth and success. The framework is useful for startups and businesses of all sizes that are looking to measure their success and optimize their marketing and growth strategies.