Global control group

The Global control group allows you to define a fixed percentage of your user base who are excluded from all marketing communications (Push, Email, In-App). Control group users still receive transactional messages.

This helps you measure how effective your messaging campaigns are by comparing results from users who received the messages to those who didn’t (the control group).

Nota

The Control group is configured at the application level.

What users are included

Only new users who sign up after you turn on the control group can be added. Pushwoosh checks each new user once and randomly assigns some of them to the group based on the percentage you set (between 1% and 15%).

Users stay in the control group unless you change the group size or disable the group. Keeping the group unchanged helps maintain accurate campaign results.

Important

Pushwoosh assigns users based on their user ID, not device. If a user’s contact methods, such as their mobile device, email address, or phone number, aren’t linked under the same User ID, Pushwoosh may treat them as separate users. As a result, they might still receive marketing messages even if one of their contact points is in the control group.

To avoid this, make sure you register all contact methods with the same User ID.

Learn how to manage User IDs for omnichannel campaigns

How the Control group affects message delivery

Marketing messages (Push, Email, In-App) are automatically blocked for control group users across all types of campaigns.

Transactional messages (like password resets or order confirmations) are still delivered. To ensure this, select Transactional message when creating a customer journey campaign or sending a one-time message.

Nota

You can select the message type (Marketing / Transactional) in campaign and one-time message forms when the Global control group is enabled.

How existing campaigns are treated

Campaigns that were created before you enabled the Global control group do not have a message type set. They are treated as transactional and are delivered to all users, including the control group. If you want such campaigns to exclude the control group, edit each campaign and set the message type to Marketing.

Learn more about marketing and transactional messages.

Working with control group users

When you enable the Global control group, Pushwoosh creates a system tag:

• Tag name: PW_ControlGroup
• Values: true (user is in the control group) or false (user is not)

You can use this tag to filter, segment, or export control group users.

Enable the Global control group

Important: Only admins can create, edit, or delete the Global control group. Roles are assigned in My Account → Users and groups. Learn how to manage roles and permissions.

1. Navigate to Settings > Global control group.
2. Click Enable.

3. Select what percentage of users will be excluded from marketing messages to measure campaign impact.

• 3%: Maximum reach
  Recommended for small apps or critical use cases where reaching more users is important and measurement accuracy can be slightly relaxed.
• 5%: Recommended for most apps
  Best default option. Provides a good balance between measurement confidence and user reach.
• 10%: Higher confidence
  Suitable for large-scale campaigns or when you need strong data accuracy to validate ROI.
• Custom (1%–15%):
  Use when you need flexibility to define your own percentage based on app size, campaign type, or business needs.

Click Apply to save your selection.

Nota

After the control group is enabled, when creating a campaign, you will see a message that users in the control group are excluded from this campaign.

Manage the control group

Edit the control group

You can adjust the size of the control group at any time from Settings > Global control group.

1. Click Edit group size.
2. Choose a new percentage (1% to 15%).
3. Click Apply to confirm changes.

Important

When you change the control group size, Pushwoosh recalculates which users are included. This can result in some users being added to or removed from the control group. This can affect how your results compare to earlier campaigns, so it’s best to make changes only when necessary.

Export control group users

To download a list of users in the control group:

1. Open Settings > Global control group.
2. Click the three-dot menu in the top right.
3. Select Export users.
4. When the export finishes, click Download CSV to save the file.

Disable the control group

1. Click the three-dot menu next to the control group settings.
2. Select Disable control group.

Disabling the group removes the control group status from all users, and they will start receiving marketing messages again. If you re-enable it later, Pushwoosh creates a new group with a new random selection.

Frequently asked questions

What users are added to the control group?

Only users who sign up after you enable the control group can be added. When a new user registers, Pushwoosh randomly decides once whether they go into the control group, using the percentage you set (1% to 15%). Users who already existed in your application when you turned on the control group are never added to it.

Do control group users receive transactional messages?

Yes. Transactional messages (e.g. password resets, order confirmations) are delivered to all users, including the control group. Only marketing messages are blocked for control group users.

Why don’t I see the Marketing / Transactional option when creating a campaign?

The message type selector is shown when the Global control group is enabled. For email campaigns, the option is also shown when the subscription preference center is enabled (either condition is enough for email). If the option is missing, enable the control group or, for email, the preference center.

What happens to campaigns created before I enabled the control group?

They have no message type set and are treated as transactional, so they are delivered to everyone, including the control group. To exclude the control group from those campaigns, open each campaign and set the message type to Marketing.

Can I change the control group size after enabling it?

Yes. Go to Settings > Global control group, click Edit group size, choose a new percentage (1% to 15%), and click Apply. Note that Pushwoosh recalculates who is in the group, so some users may be added or removed. This can affect comparison with earlier campaigns, so change the size only when needed.

What happens if I disable the control group?

All users stop being in the control group and start receiving marketing messages again. If you enable the control group again later, Pushwoosh creates a new group with a new random selection of users.

How do I see which users are in the control group?

When the control group is enabled, Pushwoosh creates the system tag PW_ControlGroup with value true (user is in the group) or false (user is not). Use this tag to filter, segment, or export control group users.

Why might a user in the control group still receive marketing messages?

Pushwoosh assigns the control group by User ID, not by device or contact method. If the same person has several contact methods (e.g. email, push device) that are not linked under one User ID, Pushwoosh treats them as different users. One of them may be in the control group while another is not, so the latter can still get marketing. To avoid this, register all contact methods with the same User ID.

What control group percentage should I choose?

The right percentage depends on your goals, app size, and how you plan to use the results. A smaller percentage (e.g. 3%) keeps more users in the audience and may suit teams that prioritize reach. A larger percentage (e.g. 10%) can give stronger statistical confidence when comparing groups. You can set a Custom value between 1% and 15% to match your needs.