Allow new subscription users to connect either personal Mailchimp accounts so they can sync their MailChimp subscriber lists and create new facebook Custom Audiences for retargeting purposes.
Need to allow multiple users to connect to their own back end and easily log in to mailchimp and facebook.
Here's an example of a service already doing this
Syncsumo [login to view URL] I would like a very similar back end version of this for my clients.
zapier currently allows users to do this but I want a backend service for clients so I can gain subscribers