they have a list of fields for "field mapping" that they say I should set up in Mail Chimp
EMAIL=email
FNAME=name:0
LNAME=name:1
On the left you have the field tag as specified in Mailchimp. On the right you have the corresponding Joomla user property. Maybe you are already asking yourself - what is the 0 and the 1 after the name? Well, in Joomla the first name and last name are stored in the same database field. We take the value in this field, we create an array out of it. 0 is basically the first value in the array, the 1 the second. So in our case 0 is the first name and 1 the second name
