ExactTarget is a commercial email management system competing against Mailchimp. If you use ExactTarget, here are modules to help you connect your Drupal data and Web site to ExactTarget.
ExactTarget competing against Mailchimp and other mail management systems. Please add your alternatives here.
I have more experience with Mailchimp and would choose Mailchimp first if starting a new Web site. In fact I would choose the Mandrill option of Mailchimp. There are reasons for choosing ExactTarget and someone with more experience of ExactTarget could add the reasons here.
ExactTarget API has functions for adding and deleting subscribers.
A list is made up of subscribers. All of your subscribers belong to the master All Subscribers list in your account. You create as many lists as you need to segment your subscribers so that you can target your email communications. For example, you can create a list for your monthly newsletter, your weekly coupon offer, and a special announcements list.
ExactTarget API has functions for working with subscriber lists.
A group is a subset of subscribers taken from a list.
ExactTarget API has functions for working with groups.
A subscriber can subscribe and unsubscribe through a Web site or a link in the email. The Webform ExactTarget module provides one way to subscribe from a Web page.
ExactTarget content includes email templates and images.
ExactTarget Email is an interface for submitting nodes as email templates.