The Mailchimp add-on keeps your audience current and lets Mailchimp's automations act on what customers actually bought.
- Create a key for WBAMS
In Mailchimp: Account › Extras › API keys. A key made for this purpose can be revoked later without breaking anything else.
- Activate and validate
Activate the add-on, open it, paste the key whole (with its -us01 style suffix) and press Validate API Key.
- Choose the audience
An existing list or, more cleanly, a new one.
- Let the e-commerce connection finish
When it reports E-commerce Connection Complete, new signups and purchases sync as they happen.
The sync looks forward
Customers who existed before you connected are not sent. Export them once from Tools › Mass Data Export and import them into Mailchimp, as Subscribed only where you hold consent.
Full guide
The complete reference is Integrations in the WBAMS documentation.