Local control groups (LCG)

Description

A Local control group (LCG) is the part of a campaign’s audience that does not participate in marketing activities. It is used for precise audience management and for assessing how the campaign affects recipients. At the moment, LCG reporting is not available.

A Global control group (GCG) works across the entire profile database and excludes selected profiles from all activities on the platform. If a profile belongs to the GCG, it cannot participate in a campaign unless that campaign is added to the GCG exception list. GCG is configured in the profile database settings. Details are in the separate GCG article.

LCG setup

Configure the local control group via the Local control group widget on the campaign editor’s main screen by clicking Configure:

Group size setup

Specify the size of the control group in percent. Fractional values are supported:

If you enable Audience limit, you can set the maximum number of profiles for the control group. The actual group size will not exceed this value but may be lower depending on the percentage and available audience.

info

Recommended LCG size — 5% of campaign audience. Too small a group may not give statistically valid results; too large lowers campaign reach.

Stratification

Description

Stratification is a method of random sampling after splitting the audience into subgroups (strata) based on selected characteristics. The audience is divided so that each subgroup reflects the composition of the full audience.

A share of profiles is selected from each stratum proportional to its size. This creates a control group with the same distribution of characteristics as the test group, which improves accuracy. The maximum number of strata depends on the number of fields and conditions configured in the system.

A stratum is a set of conditions defined by one or more criteria. Each unique combination forms a separate stratum.

A field is a characteristic used to form strata.

Stratification example

Suppose the marketer needs to split the audience by three criteria:

• City: Moscow, Saint Petersburg
• Gender: male, female
• Age: 18–30

The system forms strata for all combinations:

• Men aged 18–30 from Moscow
• Men aged 18–30 from Saint Petersburg
• Women aged 18–30 from Moscow
• Women aged 18–30 from Saint Petersburg

Stratum share calculation
Suppose your target audience consists of:

• 50% men, 50% women
• 40% aged 18–30
• 60% from Moscow, 40% from Saint Petersburg

The share of “Men 18–30 from Moscow” in the entire audience:
0.5 × 0.4 × 0.6 = 0.12 (12%)

Profiles for the control group are selected from each stratum proportionally to its share.

Stratification setup

Stratification settings are in the same window as the main LCG parameters and are available via a dropdown menu:

Set strata by one or multiple fields, defining conditions such as date ranges, numeric ranges, or lists of values. The setup is done in the UI, where you can add strata and define parameters for each:

Supported field types

You can use core and additional fields of these types:

• enum — predefined list of values
• bool — true/false
• int/float — numeric values
• string — text
• date — date field

Field conditions

For each type, different conditions are available:

• Number — range (“from–to”)
• Float — range with inclusive/exclusive borders
• String — “equals”, with multiple values
• Boolean — true, false, missing
• List — “equals”, multi-select
• Date — fixed or relative range

Stratification limits

• Minimum conditions per field — 2
• Maximum conditions — 64 total
• Maximum fields — 32

The limit is calculated by multiplying the number of conditions in selected fields.
Example: City (3 values) × Age (2 values) = 6 strata.

Note

Values in one field must not fully overlap:

• Dates — ranges must not overlap
• Numbers — ranges must not fully cover one another
• Strings/lists — no full duplication of values

Strata recommendations

• Up to 100k profiles — 5–10 strata
• 100k–1M profiles — 10–20 strata
• 1M+ profiles — 20–30 strata

Recommended number of conditions per field: 2–4. More than 5 may create overly narrow strata.

Ignoring marketing activities

Description

The Ignore marketing activities setting lets you choose activities that must send messages to all profiles, including the control group. Useful for critical communications that must reach everyone.

Examples

• Transactional notifications — order status messages
• Legal updates — changes to terms or privacy policy
• Technical alerts — system maintenance messages
• Emergency notifications

Ignore setup

Located in the same LCG settings window:

To edit the list of activities that ignore LCG, click Edit:

Audience building process

When you configure LCG and activate the campaign, the system starts the audience building process.
It also starts when LCG settings change in an active campaign.

During audience building:

• Profiles are distributed between the test group and the control group
• Mailings are paused until the process completes
• The campaign receives an additional Audience building status while its main status stays unchanged

If LCG is enabled after the campaign is already active, the control group will contain only profiles added to the campaign after activation, such as through audience expansion. Profiles initially assigned to the test group remain in the test group.

caution

If broadcasts or regular mailings are active when audience building starts, they are paused until it finishes.

LCG management

Once LCG is configured, the following actions are available:

• Edit settings — LCG parameters, stratification, ignored activities
• Delete LCG — removes the local control group and all related settings. Audience building starts, and all control group profiles move to the test group
• Export profiles — after audience building completes, you can export LCG participants via the Audience widget. Details are in the export section of the Campaigns guide.