Can I run separate control groups for different markets or audiences?

Yes. An app can have several control groups, for example one per market, and adding a group doesn't change the others. Go to Settings > Control groups and click Add control group.

For each group you set:

• Name: up to 64 characters, no colon, unique within the app.
• Group size: the share of users held back from marketing messages, from 1% to 20%.
• Mode:
• Permanent: selected once and excluded until you turn it off.
• Auto-refresh: a new group is selected at the end of each cycle (Refresh every 1, 2, or 3 months) and the previous one returns to messaging.
• Experiment with an end date: runs between the From and To dates, then everyone returns to messaging. To must be at least 30 days after From.
• Countries (optional): only devices whose Country tag matches are held out.
• Tag (optional): only devices with the tag values you choose are held out. Pick a tag that rarely changes, such as market or signup cohort.

Avoid overlaps. If the countries or tag values match users of another enabled group, the dialog warns you. Users in both groups are held out by each, which skews the statistics of both. A group with no countries and no tag covers all users, so it overlaps with every other enabled group.

Learn more: Choose a mode