Greetings.
I have an issue with Impressions not matching the data shown in the AdWords account for the same period ( and timezone ).
It is an issue with seemingly, both Keyword Performance Report and Shopping Performance Report.
It is not a case of entire days missing, but rather, each day have up to a few hundred impressions less according to the report pulled from the API, than they do according to the AdWords Interface from Google.
Any and all suggestions are welcome!