Buoyed by the spread of the Android operating system, smartphone impressions now make up more than half (56%) of the U.S. ad inventory of mobile ad network inMobi. New data released by inMobi Thursday showed Android alone accounts for 19.2% of impressions, second only to Apple's iOS, which generates 24.6% as of October.
Apple had lost almost three percentage points in share in the prior 90 days, while Android picked up 8.7 points. Trailing well behind them in third place was BlackBerry with 7.5% share, followed by Symbian with 4.5%, and Windows Mobile at 1.1%. Smartphone ad inventory overall shot up 57% in the three months ending in October, with inMobi serving 600 million monthly impressions.
inMobi's total U.S. ad market grew 25% in the third quarter, rising from 2.4 billion impressions in July to almost 3 billion in October.
When it comes to individual smartphones, the iPhone is still dominant, with 21.9% share. The Motorola Droid is a distant second, with 4.5%. However, the iPhone slipped 2.2 percentage points during the three-month period, while the four devices tracked by inMobi that gained the most share (+6 points) were all Android phones. That doesn't include the Droid, which dropped from an 8.8% share in July.
Looking at share by manufacturer, Apple was tops with 24.6% share, followed by 20.9% for Samsung, Motorola at 13.7%, Research in Motion at 8.5%, and Nokia at 7.4%. But once again, Apple's grip on the top slot is slipping, as it lost 2.9 share points while Samsung picked up 2 points on its main rival. The trend suggests that Samsung could overtake Apple as the top manufacturer, driven by its line of Android phones including the new Nexus S it just launched with Google.
inMobi expanded to the U.S. earlier this year, formally kicking off operations here in June following a soft launch at the start of 2010. The company had already built up a large presence in Asia, Africa and Europe before entering the U.S., and today says it generates 24 billion monthly mobile impressions globally. It has raised about $15.5 million to date from investors including Kleiner, Perkins, Caufield & Byers and Sherpalo Ventures.