Mailchimp for WordPress Premium adds Premium functionality to the Mailchimp for WordPress plugin.
Mailchimp for WordPress Premium Features:
Flexible, user-friendly and good looking sign-up forms for your Mailchimp list.
A myriad of integrations to easily subscribe from existing forms on your site.
Subscribe from anywhere
Show your sign-up options anywhere: posts, pages, widget areas, etc.
Customize to your need
Mailchimp for WordPress is built with extensibility in mind - you get full control.
Recover abandoned carts
Encourage subscribers to complete their purchase. The feature that pays for itself.
Know your audience
Write better emails by collecting important information about your subscribers.