Hi jfwarren21,
Thanks for hopping in the forum. During the MailChimp signup process there are a couple thank you pages. The first appears after someone signs up, this is called the sign up ‘thank you’ page. This page isn’t shown with the plugin because the success message is displayed in the page that the form is added.
Another thank you page is shown after a subscriber confirms their subscription, it’s called the Confirmation ‘thank you’ page. This page can be changed to a custom url with the plugin. This guide from the MailChimp Knowledge base has some details on adding that url: http://kb.mailchimp.com/article/can-i-design-and-host-my-own-thank-you-pages-instead-of-using-mailchimps/
There is a way to use custom urls with for both of those pages when using the embed code from MailChimp with javascript disabled. Here’s more information on grabbing that code from your MailChimp list: http://kb.mailchimp.com/article/how-can-i-add-my-signup-form-on-my-website
Let us know if you have any other questions.
-mc_d
