Google this week announced that Gmail Ads will soon be available through Display & Video 360, Google’s DSP. Google says advertisers will soon (few weeks) be able to purchase native mobile and desktop Gmail ads on DV360.
Gmail ads are billed based on engagements and not on CPM.
Gmail Ads were launched in 2015 via Google Ads (Adwords) but Gmail Ads were in beta testing since 2013. Google is launching them in DV360 in 2019.