I watched the tutorial videos but I didn't see a way to add additional input fields. My client's email signup form for Mailchimp requires email and first name fields (although I advised her against this, but it's her choice). When I use the Optin Revolution plugin, it seems that there's only one field (the email field) available, so if you fill out the popup form and submit it, it takes you to the Mailchimp error page saying "one or more required fields were not filled out", etc. I'd like to avoid this by just adding that second field to the popup. Surely I just missed something?