Once you figure out how to get the API key this works great. From your Mailchimp account, go to “Account Settings”, “Extras”, then click on “API key”. Click the button that says “Create API key”, make a label for it, then cut and paste it into the ap when it asks for it. It took me a while to research and figure this out which is why I only gave it 4 stars. They really need some instructions! Also make sure you click the box at the bottom left of the app that says “Yes, these contacts have opted-in to my list”. Hope this helps.