# Interest Targeting

Interests are also called Flight Categories. To see what Interests have already been created in the system, you'll want to use the [List Network Categories Endpoint](https://dev.kevel.co/v1.0/reference/flight-categories-1#list-network-categories) or [List Flight Categories Endpoint](https://dev.kevel.co/v1.0/reference/flight-categories-1#flight-categories-list).

Note that the user key supplied in the `user` object will override a user key set via the `azk` cookie.

## Parameters

- **networkId**  
  `int32`  
  required  
  Your account (network) ID

- **userKey**  
  `string`  
  required  
  UserDB ID for the user

- **interest**  
  `string`  
  required  
  The interest category friendly name you want to tie to the user

- **property**  
  `string`  
  Appends one or more key/value pairs to be shipped to UserDB logs. In the format `?property:Key1=Value&property:Key2=Value` etc.

## Example

### Base URL
```plaintext
https://e-networkId.adzerk.net/udb/networkId/interest/i.gif?userKey={UserKey}&interest={interest}
```

### cURL Request
```bash
curl "https://e-23.adzerk.net/udb/23/interest/i.gif?userKey=ue1-e397eb5990&interest=Sports"
```

[Returns a 1x1 transparent GIF image]