playbackend 3 means On Leaving Viewport Continues as a Floating/Slider Unit
When scrolled away, the player detaches into a floating or slider unit and plays on until completion or the viewer stops it.
When to send it
Send 3 when the player, once its original position scrolls out of view, moves into a floating or sliding unit that stays on screen until the ad completes or the viewer closes it. Sticky corner players on news sites are the common case.
Buyers read 3 as a promise that the ad stays visible, though usually smaller, so they may weigh Video.w and Video.h against the floating size. The plcmt definitions ask that later ad calls from an instream player that has turned floating report the new player size. It is confused with 1 and 2, and with old Video.placement 5, which treated floating as a placement type rather than as what happens when the player leaves view.
Example
{
"imp": [
{
"video": {
"playbackend": 3
}
}
]
}Fields that carry it
Other values in playback cessation modes
| Value | Name |
|---|---|
1 | On Video Completion or when Terminated by User |
2 | On Leaving Viewport or when Terminated by User |
The playback cessation modes list page explains the whole list and its common mistakes.