Starting mid-November, we’ll be updating AdWords API impression share reporting data more frequently. As a result, you'll be able to get the previous day's data by 12 PM (your local time). Previously, you might have had to wait up to 48 hours for the previous day’s data. This change affects the following reporting fields:
  • SearchBudgetLostImpressionShare
  • SearchExactMatchImpressionShare
  • SearchImpressionShare
  • SearchRankLostImpressionShare
With this change, you may see data fluctuate for report definitions that contain any of the above fields along with one of the following date ranges:
  • YESTERDAY, TODAY, LAST_7_DAYS, THIS_MONTH, ALL_TIME, LAST_14_DAYS, LAST_30_DAYS, THIS_WEEK_SUN_TODAY, THIS_WEEK_MON_TODAY
  • CUSTOM_DATE that includes the current date or the day before the day when you make a report request
This change allows for more real-time monitoring of search impression share. If you prefer to see more stable values, make sure the date range in your request doesn’t include the current date or yesterday if it’s not yet 12 PM in your time zone.

As always, if you have any questions, please post on the forum.