[null,null,["最終更新日 2025-08-21 UTC。"],[[["\u003cp\u003eAll creative types use delayed impressions, meaning impressions are only counted after the creative renders and sends a request back to Google.\u003c/p\u003e\n"],["\u003cp\u003eThis delayed impression process can lead to a discrepancy between winning bids and billable impressions, especially in Real-Time Bidding (RTB) scenarios.\u003c/p\u003e\n"],["\u003cp\u003eImpression billing has varying expiration windows depending on the inventory type: App Open, server-side, and podded in-stream video requests have a 4-6 hour window, while all other inventory has a 1-hour window.\u003c/p\u003e\n"]]],[],null,["# Impressions expiration\n\nAll creative types use\n[delayed impressions](//support.google.com/admanager/answer/2521337).\nThis means that impressions aren't counted until the creative renders and\nsends an impression request back to Google. Because of this secondary request,\n[RTB breakout](//support.google.com/authorizedbuyers/answer/6156706) and\n[RTB Troubleshooting](/authorized-buyers/apis/guides/v2/rtb-troubleshooting)\ncan return a greater number of winning bids than billable impressions.\n\nExpiration windows\n------------------\n\nThe expiration window for impressions-based billing events varies by inventory\ntype. The expiration window of the request in seconds is sent in the\n`BidRequest.imp.exp` field.\n| **Important:** Google records and bills for all impressions received within the following time periods. \\* [App Open](//support.google.com/admanager/answer/9351867) requests: 4 hours \\* [Server-side](//support.google.com/admanager/answer/6147120) requests: 4-6 hours \\* [Podded in-stream](//support.google.com/admanager/answer/2554762) video inventory: 4-6 hours \\* All other inventory: 1 hour"]]
