# MessageFlow Segments

MessageFlow Segments are an advanced tool that allows you to automatically and continuously group contacts based on their attributes, behaviors, and interactions with your campaigns. Unlike static segmentation, a dynamic segment is not a fixed list but a set of rules. The recipient list is regenerated at the moment a campaign is sent, ensuring it is always up-to-date.

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**Important Information:** The MessageFlow Segments service, especially its use of Custom Events sent via API, is an **add-on feature** and may be subject to additional charges.
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## **Key benefits of MessageFlow Segments:**

* **Real-time targeting:** Reach recipients based on their recent actions, such as abandoning a cart or clicking a specific link.
* **Automated recipient group creation:** A once-defined segment will always contain an up-to-date list of contacts who meet the criteria, with no need for manual imports.
* **Advanced personalization:** Create highly precise recipient groups based on complex combinations of declarative and behavioral data.

## How dynamic segments work: data sources

Our segmentation engine can build criteria based on four main data categories:

### **Declarative Data (Contact Fields)**

All standard and custom attributes assigned to a contact's profile, such as `Email`, `MobilePhone`, `FirstName`, `CreateTime`, or custom fields like `Customer_Status`.

### **Website Activity (Visits)**

Data on contacts' interactions with your website where the MessageFlow tracking script is implemented. Examples include the URL of a visited page or the number of visits.

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*Note: Please confirm the functionality and availability of this feature with our support team or your account manager)*
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### **MessageFlow System Events**

Events automatically generated by the platform in response to contact interactions with your campaigns, e.g., `MailOpen`, `MailClick`, `SmsClick`.

### **Custom Events (via API)**

The most advanced option, allowing you to send any events from your systems (e.g., CRM, e-commerce) to MessageFlow via a dedicated API. This enables you to segment recipients based on events like `product_purchased`, `plan_upgraded`, or `last_login_date`, along with all the attributes of those events.

## Creation and Configuration

For detailed instructions on creating and configuring dynamic segments, please refer to the [creating-a-new-dynamic-segment](https://docs.messageflow.com/contacts/contact-segmentation/dynamic-segments-messageflow-segments/creating-a-new-dynamic-segment "mention")