Listrak's Dynamic Content solution allows marketers to dynamically change a portion of an email based on what criteria a contact meets (or doesn't). As a result, the subject line of your email may need to be updated to reflect this differing content. Dynamic Subject Lines utilizes Liquid coding to create dynamic subject lines.

Below you will find instructions on how to set up dynamic subject lines and specify a default. You will also find examples of liquid code to create dynamic subject lines.

If you unfamiliar with Liquid, learn more about the coding language.

If you are ready to create your code, learn more about:

If you are unfamiliar with Liquid Coding, the definitions below are going to be helpful when getting started.

Liquid is a template language that allows the loading of dynamic data into an element of an email or website. This coding language is used in many places, including Shopify, who originally created it.

An object is a variable in liquid that can be used as part of the conditional logic to determine what version a contact should receive and can also be used as personalization in the subject line. In Listrak these variables come from your profile fields.

A filter in liquid is very different than a filter in Listrak's system. A liquid filter is used to modify the appearance of an object variable. For example, a liquid filter can capitalize a variable or transform the text so that is appears in all uppercase.

A tag is used to control what a contact will and won't see when using objects and filters. A tag begins with {% and ends with %}. Any input between these two will not visually appear.

Liquid allows the use of if/els logic to determine which version of content (in this case subject line) a contact would receive. The if/els logic can evaluate an object's value. For example, send different subject lines based on a contact's loyalty tier or change a contact's subject line if the last browsed category profile field contains a specific word.

When creating a dynamic subject line using liquid logic, you will create two main components 1) the default option and 2) the if/els statement that specifies the other subject line options.

The default option is the subject line a contact will receive if they do not meet the criteria set up in the if/els statement. This fallback is used to ensure all contacts receive an email that contains a subject line. The default option is created in Listrak's standard subject line in the message creation experience.

The if/els statement is used to determine which version of a subject line a contact should receive. The if/els statement evaluates an object for a specific value and then specifies the result that should happen when the value is found.

Operators are used to determine what criteria needs to be found in the object in order for someone to receive the specified subject line.

💡 The values used in connection with these operators should be enclosed in quotation marks.

For example, the if/els logic could evaluate the variable of favorite season. In the table below you will see the value the statement is looking for and the result (subject line) that would appear. In this example, an operator like equals can be used to specify the different seasons.

When using data such as checkbox and radio button data, the system will look for specific values based on if the values are selected.

💡 The value will depend on the value used during the initial contact import. Export your contacts to see the specific values stored in their profile fields.

⚠️ These values are stored as text and must be enclosed in quotation marks

In the example below, a contact may have one of multiple values in their field. The if/els statement will evaluate to look for one of the three values listed here (1, on, or TRUE) and send the specified subject line if a contact has one of these values.

Filtering in Liquid provides a way to change the way an object appears. Common types of filters include: show the whole output in uppercase, capitalize the first letter, add a specific value to the beginning, or adding a specific value to the end. Filters are often used when the object appears in the subject line. Below you will find a few examples of common filters.

Append a pipe and the specific action that should be taken after the field name to add a filter to the object.

Learn more about filters available in Liquid.

When creating a dynamic subject line, you will always be required to specify a default subject line. This subject line will be sent to anyone who does not meet any of the logic specified.

The default subject line is created in the message builder. Navigate to: Messages > Email New Broadcast Email.

Default subject lines can include personalization, such as a contact's first name, stored in a profile field. You can use the Personalization Control Panel to create the formatted tag.

💡 If your email contains dynamic content, the default subject line should correspond to your last variation.

When creating the dynamic versions of your subject line, the personalization fields are a critical element. Profile fields serve two purposes: 1) personalize the content of a subject line and 2) determine which contact should receive each version of a dynamic subject line.

After you click Add Dynamic Subject Line in the New Email Broadcast experience, the dynamic subject line experience will open. Here you can create your If/Els statements using Liquid coding.

To include a Listrak profile field object in your code, the drop-down in the top right will contain all profile fields for your current list.

💡 Use the search function to quickly find a specific profile tag.

Selecting a tag will add it to the code builder on the left side. Learn more about how these tags are written below.

In the code blocks below are the common layouts you may find when adding a profile field into Liquid. Here are a few pointers to help understand the syntax.

No space in either name:

Space in one name:

Space in both names:

While every dynamic subject line requires a default value, the number of potential subject lines may depend on your goal. You may have only one additional subject line that may appear. This is especially useful when the object you are evaluating is a profile field created as a checkbox or radio button. In this case, only two options are available. One of these objects will become your default value and you can use the if statement to specify the subject line for the second option.

💡 Key Coding Components

An If/Els statement allows you to specify multiple potential subject lines by specifying multiple options for the value a contact should meet. An If/Els statement is useful when a text field operator is being used and multiple text inputs are possible.

💡 Key Coding Components

📌 In the example above, the subject line dynamically updates the type of VIP and amount of points earned based on the tier in the Current Tier Level profile field in Listrak. If a contact does not meet one of these values, they will receive the default subject line set in the New Email Broadcast screen.

Liquid filtering is typically set up find and target contacts who have or do not a value in a particular field. Using this concept, the value liquid should evaluate is an empty value or nil. Another possibility is unknown. In the example below, if a contact's first name is not empty (is not nil or is not unknown) the subject line will then contain their first name. If a contact's name is empty they would then receive the default subject line.

In the loyalty example above, a single field is evaluated multiple times to search for a specific value. However, you may want to evaluate multiple fields to determine if a contact has at last one attribute, or you may want to accept multiple values in a single field.

Multiple values can be connected with the and and or operator. Operators will be evaluated from left to right.

📌 In the example above, the subject line is dynamically updated if a contact has one of three values in their loyalty tier profile field. If a contact has the value of Bronze, Silver, or Gold, they will receive the dynamic subject line. Any other value will receive the default subject line.

These and or conditions can also be used in elsif statements.