Ad management service MoPub today published its Q2 2012 Mobile Advertising: Marketplace Report which finds growth in mobile ads, especially with Android and social networks.

Overall, MoPub’s report finds that demand for real-time bidded ad impressions increased significantly through Q1 and Q2 of 2012, with a 300 precent increase in average bids per ad request.

In terms of devices, the report shows Android is becoming more popular, and advertisers are taking notice. While advertisers still pay 86 percent more to reach a developer’s audience on iOS, Android is stealing advertiser share as it increases its impression volume. The iPhone’s share of MoPub’s auction volume dropped from 48 percent in April to 44 percent in June, while Android’s rose from 28 percent to 38 percent in the same timeframe.

As the slide below shows, the social networking category showed the most growth by far, but business, lifestyle, and health and fitness apps are growing as well, both in terms of impressions and average effective cost per 1000 impressions (eCPM).

Find the full report here.