A plugin for adding MailChimp's Goal tracking code to your WordPress site.
From your MailChimp dashboard:
In order for Goal to track subscribers, you'll want to check two things:
First, make sure Goal has been enabled in your MailChimp account. After logging in to Mailchimp, click on your profile name to expand the Account Panel and choose Account Settings. Click the Extras menu and choose Integrations. From the list of integrations, click on the Goal option and click Enable.
Second, in order to track subscribers, you'll need to send a campaign with Goal tracking enabled.
Right now, Goal is only available for paid accounts.