One of the most important KPIs doesn't seem to be available via Youtube-Analytics-API. I can't get the total of thumbnail-impressions that have been shown to users. With that I could aggregate the impression-CTR using the views from certain traffic-sources (YT_SEARCH etc.). The docs don't seem to offer anything that would help me though.
Youtube-Reporting-API seems to have the same metrics as Youtube-Analytics-API. So I guess trying to use the Reporting-API would not help me either.
Is there any way to retrieve the number of thumbnail-impressions or the Impression-CTR programmatically? Any workaround? Am I missing something obvious? Or is there any intention of making that metric available via Analytics-API soon?
There is some very old, unanswered posts that may relate to my problem:
How to access new YouTube Analytics Metrics (Impressions, Impressions CTR) from API
Are Thumbnail Impressions/Views available through YouTube Analytics API?
There is a thread in google's issue-tracker that clearly states that (for now) it is NOT possible and in fact it is intended behavior (won't fix)!
I'll keep checking the API's Revision-History and try to keep this answer up to date.