Best Practices

Recommended setup

Start with Campaigns report for performance data

This single entity gives you open rates, click rates, bounces, and unsubscribes per campaign. It's faster to pull than combining Campaigns + Audience activity and is the right starting point for most email reporting dashboards.

Use one source per audience for audience-level entities

Audience contacts, activity, and growth data are scoped to a single audience. If you manage multiple lists, add one source per audience in your data flow and use the Append transformation to combine them into one destination table.

Apply date filters to Campaigns report for ongoing flows

Use the "Sent since date" filter to limit Campaigns report pulls to recent sends. This keeps run times short and avoids re-loading historical data you've already captured.

Data refresh and scheduling

Wait 24–48 hours before pulling campaign stats

Mailchimp continues tracking opens and clicks after a campaign is sent. Pulling the Campaigns report too soon means you'll capture incomplete engagement numbers. If you schedule a daily refresh, this self-corrects over time.

Schedule Audience exports less frequently than Campaign reports

Contact lists don't change as fast as campaign metrics. A daily or weekly Audience export is usually sufficient, while Campaigns report can run more frequently during active sending periods.

Performance optimization

Filter large audiences to avoid timeouts

Pulling 100k+ contacts in a single run frequently times out at the 9-minute API limit. Use advanced filters to pull by status (e.g., subscribed only) or use the Columns setting to limit which fields are returned — fewer columns means faster runs.

Use the Columns setting to trim unnecessary fields

The Audience (list of contacts) entity returns many fields by default. If you only need email, status, and tags, specify only those columns. This reduces payload size and speeds up both the run and destination load.

Common pitfalls

Audience activity is the heaviest entity. For large audiences, pulling Audience activity can exceed the 9-minute timeout even with filters applied. If you need per-contact event data for a large list, contact Coupler.io support to discuss options before building a production flow around this entity.

Do

• Select a specific audience before running audience-level entities

• Use the Append transformation when combining data from multiple Mailchimp audiences

• Confirm a manual run succeeds before setting up a schedule

• Use Manager-level Mailchimp credentials to avoid 403 errors

Don't

• Pull Campaigns report immediately after sending — wait for engagement to settle

• Use the same destination sheet for multiple data flows without an Append setup — runs will overwrite each other

• Rely on Audience activity for real-time tracking on large lists

• Expect Customer Journey data to be available — it's not currently supported as an entity