一、定义-impression
This object describes an ad placement or impression being auctioned. A single bid request can include multiple Imp objects, a use case for which might be an exchange that supports selling all ad positions on a given page. Each Imp object has a required ID so that bids can reference them individually.
The presence of Banner, Video, and/or Native objects subordinate to the Imp object indicates the type of impression being offered. The publisher can choose one such type which is the typical case or mix them at their discretion. However, any given bid for the impression must conform to one of the offered types.
二、翻译
impression在百度百科上被翻译为印象，定义为：放置广告图像的网页每一次显示，就是一次印象。
Impression描述一次广告投放或者被拍卖的印象。一个竞价请求包括多个Imp对象，一个典型的应用场景是：一次交换支持销售一个页面所有的广告位。每一个印象对象包含一个请求ID，因此竞价平台可以单独引用他们。
三、属性
| Attribute |
Type |
Description |
| id |
string; required |
A unique identifier for this impression within the context of the bid request (typically, starts with 1 and increments. |
| banner |
object |
A Banner object (Section 3.2.3); required if this impression is offered as a banner ad opportunity. |
| video |
object |
A Video object (Section 3.2.4); required if this impression is offered as a video ad opportunity. |
| native |
object |
A Native object (Section 3.2.5); required if this impression is offered as a native ad opportunity. |
| displaymanager |
string |
Name of ad mediation partner, SDK technology, or player responsible for rendering ad (typically video or mobile). Used by some ad servers to customize ad code by partner. Recommended for video and/or apps. |
| displaymanagerver |
string |
Version of ad mediation partner, SDK technology, or player responsible for rendering ad (typically video or mobile). Used by some ad servers to customize ad code by partner. Recommended for video and/or apps. |
| instl |
integer; default 0 |
1 = the ad is interstitial or full screen, 0 = not interstitial. |
| tagid |
string |
Identifier for specific ad placement or ad tag that was used to initiate the auction. This can be useful for debugging of any issues, or for optimization by the buyer. |
| bidfloor |
float; default 0 |
Minimum bid for this impression expressed in CPM. |
| bidfloorcur |
string; default “USD” |
Currency specified using ISO-4217 alpha codes. This may be different from bid currency returned by bidder if this is allowed by the exchange. |
| secure |
integer |
Flag to indicate if the impression requires secure HTTPS URL creative assets and markup, where 0 = non-secure, 1 = secure. If omitted, the secure state is unknown, but non-secure HTTP support can be assumed. |
| iframebuster |
string array |
Array of exchange-specific names of supported iframe busters. |
| pmp |
object |
A Pmp object (Section 3.2.17) containing any private |
| ext | object |
Placeholder for exchange-specific extensions to OpenRTB |
