The attribute campaign_id in orders is not being used by Mailchimp's API anymore, Mailchimp handles campaign revenue attribution to orders internally; sending requests to the API containing it is unnecesary and can cause previous orders of a customer who made an campaign related order to be misattributed to that campaign as well despite being unrelated.
The attribute
campaign_idin orders is not being used by Mailchimp's API anymore, Mailchimp handles campaign revenue attribution to orders internally; sending requests to the API containing it is unnecesary and can cause previous orders of a customer who made an campaign related order to be misattributed to that campaign as well despite being unrelated.