From MailChimp, Klaviyo pulls in the following data:
- When someone received, opened or clicked a particular email
- Emails who have unsubscribed or bounced (these are added to your suppression list in Klaviyo)
- Existing lists in MailChimp
- Contacts' MailChimp Ratings
If you choose to sync existing lists from MailChimp to Klaviyo, you can choose to either sync all of your lists or only specific lists.
If you choose to sync only specific lists AND you enable the option "Collect open and click data for MailChimp campaigns," all contacts in your MailChimp account will be imported into Klaviyo -- regardless of whether or not they're in the specific lists you've chosen to sync. So, while syncing specific lists will recreate them in Klaviyo, it will not necessarily limit the number of contacts imported from MailChimp.
Keep in mind that only names and email addresses will sync; to migrate over custom properties that may be attached to contact profiles in MailChimp, see below.
If you delete people in MailChimp, they will not be deleted in Klaviyo. However, if someone is added to a MailChimp list, they'll be added to Klaviyo within an hour. We receive historical data from MailChimp from the last 90 days; if you are syncing a large number of contacts from MailChimp, this may differ.
The integration brings data over every 30 minutes for lists. For campaigns, it pulls data every 15 minutes on the first day and checks less frequently as time passes.