Target groups - Dynamic filters > Search rule setup > List split using MOD

List split using MOD

In some cases it may be useful to select only a fraction of the recipients selected for a particular target group. For instance, you may want to test the success of a mailing by sending it to one tenth of customers only. The OpenEMM calls this type of selection a list split. The system uses the customer ID (CUSTOMER_ID field) in connection with the MOD operator (modulo function). The OpenEMM assigns customer IDs at random for each new entry into the recipient database. They are therefore not consecutive numbers, but numbers in a statistically equal distribution (for practical applications).

You may remember the modulo function from your maths class. It calculates the residual from a division by a whole number. Let us take an example. 87 MOD 10 results in 7. First, you divide 87 by 10, which results in 8 (without decimal places). 8 times 10 is 80, 87 minus 80 is 7 which is the calculated residual.

Now, the MOD operator of the OpenEMM selects recipients whose modulo residual matches the rule specified. By entering 5 into the last field of the search rule, you select all customer IDs with a modulo residual of 5. In other words, you select one fifth of all addresses available. The number 10 selects one tenth of addresses, and the digit 3 allows you to select one third. If you wanted to highlight one thousandth of your addresses only, you would need to enter the value 1,000.

One big advantage of the MOD method is the repeatability of the result. Each time you apply a MOD rule to the database, the same recipients are filtered by the OpenEMM, since a recipient’s customer ID never changes. This is important if you are planning a multi-stage mailing where your target group receives several emails.

The following example shows a selection with 5 as the modulo value:

1.In the navigation bar, select Target groups, then New target group. To the right, the entry dialog for a new target group is displayed.
2.Fill in the Name and Description. You may want to choose a name that alludes to the MOD function application; you will then find your target group more easily at a later stage.
3.Under New rule select customer_id from the second drop-down list. This is the customer ID that the OpenEMM automatically assigns to each new recipient. The relational operator drop-down list should be set to MOD.
4.Now enter 5 into the reference value box. Click on Add to close the rule.
Fig. 6.2: This is how you create a new modulo rule with the factor 5.

Fig. 6.2: This is how you create a new modulo rule with the factor 5.

5.The system now displays the rule under Target group definition. Behind the modulo value, there is a new drop-down list for a relational operator, followed by an entry box. The first part of the search rule results in the residual value. The last entry field is used to select which residual value should be calculated. To select one fifth of all recipients the value = 0 suffices. This will select all recipients whose CUSTOMER_ID is divisible by 5.
Entering 4 here will also select one fifth of recipients, but only those whose residual is 4. In other words, you can select a different fifth of your target group by changing the residual.