Active View CPM in Google Adsense:
Active View CPM means, “Active View cost-per-thousand impressions”. With Active View CPM bidding, promoters or advertisers bid on 1000 viewable impressions. Then they only pay for all the impressions that are marked as viewable. Marking impressions as viewable means, when at least 50% of the google ad is displayed on the screen for at least 1 second.