We are setting up Analytics for the company, and have succesfully made a Instance for the website.
When we are looking at adding Mail Chimp / Facebook etc, do we create a new instance for each new application ?
Your site should be consistently tracked using on version of the GATC.
For Facebook and email that drives the user back to your site you'll tag your destination URL;s with custom campaign parameters.
More on that here:
Mailchimp has a checkbox that you can tick and it will do this for you.
I saw the checkbox in the Mailchimp, but do i need to create a new property for custom domain? for example, for mailchimp only or i can used my existing properties in the google analytics,