Interesting way to launch a service

Mailchimp is offering a 2% discount to anyone who signs up for their new “two factor security for web apps” service called Alter Ego.

The whole two-factor security is – in itself – a worthy topic, but I’m saving this technique in a post because it’s interesting to see how a successful company – Mailchimp – is leveraging their existing user base to slowly build adoption of their new tool.