Note: this example predates the introduction of the MailChimp Integration extension. I recommend that you use that extension instead as it is far easier to use and also utilizes the latest MailChimp API (version 3.0).
Here is an example of a simple integrating MailChimp with the WP-Members registration process. This could be modified to suit similar integrations as long as there is an API to hook into. Continue Reading →