Millennial Media Says Kindle Fire Impressions Growing 19 Percent Each Day

We still don’t have any exact figures from Amazon (NSDQ: AMZN) for how many Kindle Fire tablets it has sold, but the latest figures out from mobile ad network Millennial Media are the latest to suggest that it is selling very well, and that people are using the device to consume ad-based content.

Millennium, which bases its monthly data on mobile ads distributed across its multi-platform network, says that ad impressions on the Kindle Fire have been steadily growing since launch, at a rate of about 19 percent daily. While 19 percent doesn’t sound like a dramatic number, that works out to hundreds of millions of ad impressions every month, said the ad company.

Millennial also noted that the Fire tablet’s ad impressions has “slightly outpaced” impressions on the iPad when it first launched, in early 2010.

That could imply that the Kindle is more popular than the iPad, but in reality the comparison is not entirely like-for-like: the iPad was effectively the first tablet product on the market; two years on and not only are developers creating more content for these devices, but peoples’ tablet consumption habits have also evolved.

Elsewhere, Millennial’s numbers reflect a lot of the same trends that we’ve seen in previous months: Apple’s iOS is currently growing at a rate of seven percent, but it continues to lag behind Android in terms of impressions. Still, the iPhone stands out as the most popular single device on the ad network, accounting for nearly 14 percent of all ad impressions. The BlackBerry Curve ranks in second position, but several percentage points behind the iPhone, with the others trailing closely behind.

Notably, not one Windows Phone 7 device made it to the top-20 list: