From 0 to 1.3 million users (1 hack)

How did Unroll.me manage to gain 1.3 million users in just 3 years:

1. First, they discovered a really hot, massive problem – cluttered email inboxes.

2. They offered a simple solution for free – you can unsubscribe from all newsletters you are no longer interested in.

3. After the launch, tech blogs were happy to write about an app that
solves a big problem for their readers. This helped them to get their
first thousands of users.

4. Right after you start using the app and choose 5 newsletters to unsubscribe from, Unroll.me shows a pop-up “In order to unsubscribe from more than 5 subscriptions, help out by sharing on Facebook, Twitter, or via email”.

Result: 1.3 million users virally