Just noticed this new ad on my blog post I just published on history of internet explorer version over time, I noticed the twitter ad of some promoted accounts through google adsense displayed under my blog post title as shown in the image below.
As you can see in the image above, the ad is about some promoted account on twitter on windows 7 tweets. The advertisement also displays a button which says follow me on twitter, which means if you click on this ad it will take you the profile page of this promoted account where you might follow this account.
I have first time seen twitter advertising promoted accounts through google adsense, not sure about the conversion in return they are getting for these ads. This seems another way for twitter to approach more users and get followers for promoted accounts.
Related Read - What Is Twitter Promoted Account?