Dave McClure is the guy behind “Pirate Metrics”.

AARRR, a simple acronym, but extremely powerful! Dave is founder of 500 Startups too.

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.