Measure impressions
In the Messaging API, the statistics include information about various user actions. This page focuses on impressions among them.
- Aggregation environment
- Endpoints for obtaining statistics
- What is an impression?
- Impression measurement logic
- Usage precautions
Aggregation environment
Statistics, including impressions, are aggregated based on the LINE app for iOS and Android.
Messages viewed on the PC version or Chrome version of LINE aren't counted in the statistics.
Endpoints for obtaining statistics
You can use these endpoints to get statistics about how users interacted with messages you sent:
What is an impression?
An impression in the Messaging API refers to when a user enters a chat room and views a message sent from a LINE Official Account. Impressions are sometimes also referred to as message opens.
Impression types
There are two types of impressions: unique impressions and impressions. The impression measurement logic described in this document applies to both types. However, note that the number of times they are measured differs.
The impressions that can be retrieved through the endpoints for obtaining statistics are as follows:
| Property | Impression type | Description |
|---|---|---|
overview.uniqueImpression *1 | Unique impression | Number of users who opened the message. The number of people who displayed at least one bubble. Each message is counted only once per user. |
messages[].uniqueImpression *2 | Unique impression | Number of users who displayed the bubble. Each bubble is counted only once per user. |
messages[].impression *1 | Impression | Number of times the bubble was displayed. If the conditions are met, each bubble may be counted multiple times per user. |
*1 The property containing the impression value in the response of the Get user interaction statistics and Get statistics per unit endpoints.
*2 The property containing the impression value in the response of the Get statistics per unit endpoint.
Message and bubble concept
A message consists of one or more message objects. You can send up to five message objects in a single request.
In the Messaging API, a bubble refers to a single message object. Message objects include various types such as sticker message objects and image message objects. Whether they visually appear as a speech bubble or not doesn’t matter.
This illustration shows an example of a message composed of three bubbles. Although bubble 2 and 3 don't have the same speech bubble shape as the text message object in bubble 1, each is treated as bubbles for impression measurement.
When this message is sent and the user opens the chat to view it, the single bubble that's displayed triggers the counting of overview.uniqueImpression. messages[].uniqueImpression and messages[].impression are counted separately for each bubble.
For more information, see Get user interaction statistics and Get statistics per unit in the Messaging API reference.
Actions that aren't counted as impressions
Impressions are counted only when a user enters the chat room and views a message sent from a LINE Official Account.
However, if the user perform one of these actions that marks a message as read without entering the chat room, it won't be counted as an impression.
| OS | Operation |
|---|---|
| Android |
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| iOS |
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Impression measurement logic
This section explains the specific measurement logic for impressions.
- Display message bubbles at 100%
- Duplicate counting doesn't occur when scrolling
- About carousel messages
Display message bubbles at 100%
Impressions are counted when a user enters a chat room and views a message sent from a LINE Official Account. At that time, the message bubble must be 100% visible on the screen.
These are examples of bubbles that are 100% visible and those that aren't.
| Description | Image |
|---|---|
| This area's bubble is 100% visible. |  |
| This area's bubble isn't 100% visible. |  |
| Display | Description | Image |
|---|---|---|
| ✅️ 100% visible | The bubble displayed in the green area is fully visible, so it's counted as an impression. |  |
| ❌️ Not 100% visible | The bubble displayed in the red area overlaps with the rich menu and isn't fully visible, so it isn't counted as an impression. |  |
| ❌️ Not 100% visible | The bubble in the red area overlaps with the service menu bar and isn't fully visible, so it isn't counted as an impression. |  |
| ❌️ Not 100% visible | The bubble in the red area is too tall to fit within the chat window, so it isn't fully visible and therefore not counted as an impression. |  |
"100% displayed" means that both the top and bottom edges of the target bubble are visible within the user's window at some point before leaving the chat room.
Even if the entire bubble can't be displayed at once, as in the previous examples, scrolling or closing the rich menu so that both the top and bottom edges of the hidden bubble become visible will count as 100% displayed and the impression will be recorded.
Duplicate counting doesn't occur when scrolling
Once an impression is recorded, it isn't counted again while the user remains in the same chat room, even if they scroll back to display the same message multiple times.
However, if the user returns to the chat list and then re-enters the chat room to view 100% of the messages, it's counted as a new impression.
A unique impression is measured only once per user, so it doesn't increase even if the user re-enters the chat room.
About carousel messages
If you send a message that uses a carousel using Flex Message, impressions aren't counted multiple times even if a user scrolls horizontally to display the carousel.
For messages using a carousel, the impression is counted once when all edges (top, bottom, left, and right) of the bubble are displayed.
Usage precautions
Note these points when measuring impressions:
- Make sure that it's within the measurement period
- Avoid making the message too tall
- Avoid interfering with the rich menus or the service menu bar
Make sure that it's within the measurement period
Statistics, including impressions, are only collected for 14 days (1,209,600 seconds) from the time the message was sent. It isn't updated after that. When using the Get statistics per unit endpoint, you can specify the aggregation period, so make sure that the specified date is within the measurement period.
Avoid making the message too tall
If you send a message that is extremely tall, the entire message may not be displayed in the chat room, and impressions may not be counted as expected. Adjust the message to an appropriate length.
Avoid interfering with the rich menus or the service menu bar
If your LINE Official Account uses a rich menu, bubbles may overlap with it in the chat room and prevent the full bubble from being visible. As a result, impressions may not be counted as expected.
Also, if you're using the service menu bar displayed at the top of the chat room, similar issues may occur.
Adjust the length of messages and the size of rich menus to prevent these issues.