Start delay modes value 0 means Pre-Roll

Pre-roll: the ad plays before the content starts.

List: Start Delay ModesValue 0

When to send it

Send 0 when the ad plays before the content begins, in the first break after the viewer presses play. It is carried in Video.startdelay for video and Audio.startdelay for audio, and it has meant pre-roll since OpenRTB 2.0.

Buyers price pre-roll on high completion and attention, since the viewer has just chosen the content and is waiting for it. The usual mistake is sending 0 for every placement, including outstream units with no content, which leads buyers to price outstream as instream. Pair 0 with a Video.plcmt that has content, 1 or 2, and with Video.podseq 1 when it is the first pod in the stream.

Example

{
  "imp": [
    {
      "audio": {
        "startdelay": 0
      }
    }
  ]
}

Fields that carry it

Other values in start delay modes

Value	Name
`>0`	Mid-Roll (the value is the start delay in seconds)
`-1`	Generic Mid-Roll
`-2`	Generic Post-Roll

The start delay modes list page explains the whole list and its common mistakes.