> Shopify has had growing concerns about Mailchimp’s app because of the poor merchant experience and their refusal to respect our Partner Program Agreement. Our terms require app partners to share all important data back to the merchant using Shopify’s API to help them run their businesses.
Mailchimp:
> Throughout these negotiations, we refused to agree to terms that jeopardize our users’ privacy and require us to hand over customer data acquired outside of Shopify. From our perspective, that's not our data to share.