Interests vs. contact fields

When you want to store information about your contacts, Flexmail gives you two main tools: contact fields and interests. Both attach data to a contact, but they work differently and serve different purposes. Choosing the right one affects how you can segment, personalise, and automate.

The core difference

Contact fields store facts about a contact. A contact field is data you know about someone: their company name, their region, the date they signed their contract, how many orders they've placed. These are objective, stored values.

Interests express what a contact wants to receive or how they've behaved. A contact is subscribed to "Newsletter", or tagged with "Attended webinar March 2025", or marked as "Dog owner". It's something that can be on or off, and it can change over time as the contact's behaviour or preferences change.

Side-by-side comparison

When to use a contact field

The information is a fact, not a preference

If you're storing something objective about a contact, their city, their account number, their contract renewal date, the number of products they've bought, use a contact field. The value is what it is, regardless of what the contact wants.

You need to do calculations or comparisons

Contact fields support operators like "is greater than", "is smaller than", and "is before". A numeric field for "total orders" lets you segment contacts who've ordered more than five times. An interest can't do this, it's either on or off.

You need to store a date

Birthdays, contract dates, renewal dates, event attendance dates, these all belong in date-type custom fields. Flexmail can segment on date fields with conditions like "is before today" or "equals today", which makes them essential for time-based automation.

You need a structured set of options

A multiple choice field lets you define a fixed set of values, for example, "Contact type" with options Customer, Prospect, and Partner. This gives you clean, consistent data that's easy to segment and export.

When to use an interest

You want contacts to manage their own preferences

Public interests appear on a contact's profile page. Contacts can subscribe and unsubscribe themselves. This is the right tool when you want to give contacts control over what they receive, for example, letting them choose between a product newsletter, promotional emails, and a monthly digest.

You want to tag contacts based on what they click

With link tracking, you can assign an interest to a specific link in your email. Any contact who clicks that link is automatically tagged with the interest. This builds preference data passively, based on actual behaviour rather than what someone says they want. A contact field can't be updated this way.

You want to trigger automations based on subscription changes

Workflows can be triggered when a contact subscribes to or unsubscribes from an interest. This is useful for preference-based automation: when someone subscribes to "Product launch alerts", a welcome workflow starts automatically.

You want to track opt-in categories

If your communication is divided into clear content categories, newsletter, promotions, event invitations, interests are the natural fit. Each category becomes one interest, contacts subscribe to the ones they want, and you segment by interest when sending.

Using them together

The most effective setups combine both tools. For example: a contact field stores "Contact type: Customer" and a segment selects all customers. Within that segment, interests show which customers want promotions, which want the newsletter, and which want product updates. A campaign is then sent to customers who are both of the type "Customer" and subscribed to "Promotions".

Neither tool alone gives you this level of precision. Contact fields provide the objective classification; interests provide the expressed preference.

Common mistakes to avoid

•        Using a multiple choice field instead of interests for content preferences. See the support tip above, interests are almost always the better choice for anything that relates to what contacts want to receive.

•        Storing behavioural data as public interests. If you're tagging contacts based on internal classifications they shouldn't see, make sure those interests are set to private.

•        Using an interest when you need a value. If you need to store "subscription tier: Gold", that's a contact field with a multiple choice type, not an interest called "Gold".

•        Mixing up the two in segments. A segment condition on a contact field uses operators like "is" or "is greater than". An interest condition uses "is subscribed to" or "is unsubscribed from". Make sure you're using the right condition type for what you're filtering on.

Next steps

• See "Get started with interests" for a full overview of how interests work and how they're assigned.
• See "Create and manage an interest" to set up your first interests.
• Explore contact fields in Settings > Contact fields to review your current field setup.
• Build a segment that combines a contact field condition and an interest condition to see how the two work together.