Android is rapidly escalating its presence in the mobile space with the operating system increasing 15 percent month-over-month, according to a new study by Millennial Media.

The company?s July Mix Report also found that Android had a 61 percent share of overall smartphone impressions and was in the top spot for the eight straight month.

?July was another strong month for Android, and the OS increased 15 percent month-over-month,? said Mack McKelvey, senior vice president of marketing at Millennial Media, Baltimore, MD. 

Mobile research
According to the Millennial Media study, manufacturers that are building Android-based devices are also seeing huge growth.

For example, Samsung grew 28 percent month-over-month and was the second leading manufacturer on Millennial?s network ? behind Apple.

Additionally, Motorola was the fifth leading manufacturer and had three phones in the top 11 mobile phones.

When breaking down ad spend from applications on its network, Millennial saw that 48 percent came from Android apps, while 43 percent came from iOS apps.

Thirty-three of the impressions on Millennial?s network came from consumers on a Wi-Fi network.

Of the Wi-Fi impressions, 53 percent were from smartphones and 42 percent were from connected devices.

Five percent were from feature phones.

?For the first time ? we broke out all the Wi-Fi impressions on our network, which make up 33 percent of the total impressions we see,? Ms. McKelvey said.

?Consumers are increasingly using both their mobile phones and connected devices more inside the home, so we expect both categories to continue driving a significant number of impressions via Wi-Fi,? she said.

Continued research
The study also found that Windows Phone 7 impressions grew 71 percent month-over-month and since March 2009, Apple, HTC and Huawei all more than doubled their share of impressions.

In addition, Millennial found that gaming apps made up 29 percent of app impressions on its network and increased 35 percent month-over-month.

Health and Fitness app impressions also grew 13 percent month-over-month.

Calorie counting and recipe apps made up two thirds of the Health and Fitness category.

?The Health and Fitness vertical was number 7 on our list of top global mobile ad verticals, and saw app impressions grow 13 percent in the last month,? Ms. McKelvey said.

?This is a vertical that has grown tremendously in the last year ? it was not in the top 10 verticals in July 2010, and we expect Health and Fitness advertisers to continue coming up with creative ways to leverage the mobile space.?