Dave McClure is the guy behind “Pirate Metrics”.
Regarding AARRR, you need to understand that developing customers can be categorised in some important steps:
A – Acquisition, gathering customers to the process.
A – Activation, making leads to become real customers. So… they are using your service.
R – Retention, making sure people love your product and want to continue using it.
R – Referral, they love so much they want to tell other people about you. You are important.
R – Revenue, you get to keep other people money in exchange for a great customer service and quality. 🙂
Here’s a presentation about AARRR metrics:
And here’s a great biz talk with Dave McClure and Jason Calacanis (This Week in Startups):
If you are looking for some material in Portuguese related to AARRR, check this presentation from Rafael Helm.