One corollary may be the launch of the iPhone 4S in mid-October, propelling ads to Millennial. Another is the rise of Research In Motion's BlackBerry OS ad share, which climbed from 13 percent to 17 percent for November.
Apple iOS, including the iPhone, iPad and iPod touch, has a total impression of 26 percent, compared to 29 percent for Android, spanning 14 handsets. Moreover, the iPhone grew 8 percent month-over-month and still controls the No. 1 mobile phone ranking, accounting for 14 percent impression share alone.
Smartphones commanded 70 percent of Millennial's smartphone, feature phone connected device impression mix. Connected devices grabbed 16 percent of the impressions.
But the Kindle Fire's emergence as a credible Android tablet is the real growth story for the month.
Millennial, which now counts ad impressions for connected devices such as tablets and smartphones together, said Kindle Fire impressions have grown at an average daily rate of 19 percent since the e-commerce launched the $199 tablet Nov. 15.
Millennial said the Kindle Fire is seeing a "monthly run rate of hundreds of millions of impressions," slightly outpacing impressions from the first iPad's launch in 2010.
"Since its release in mid-November, the Kindle Fire has made an impact on the connected device market right out of the gate with early signs of strong consumer adoption," Millennial said in its report.
"Though the Kindle Fire has been introduced into a more mature tablet market than the market which greeted the original iPad, the integration of Amazon's robust digital entertainment library and the $199 price point may also have helped drive this early use by consumers.
Indeed, ads aren't the only part of the mobile ecosystem the Android-based Fire is affecting. Despite some balky navigation and browser bugs in the slate, financial analysts are modeling for the Fire to sell 4 million to 6 million units this quarter.
IDC said the Fire will push Android's tablet market share to 40 percent to close out the year, nibbling some share from Apple's iPad.