As a leading mobile advertising network, AdMob Inc. has the perch to identify key trends in the mobile ecosystem. Well, November revealed how a key phone is punching above its weight.

You guessed right: it's the Apple iPhone, which continued its dramatic growth in the United States. The AdMob data on how mobile Web is consumed on the iPhone is worth noting.

"We've observed that publishers are sending mobile-specific content to the iPhone rather than the HTML Internet pages," said Jason Spero, vice president of marketing at AdMob, San Mateo, CA.

"This is interesting as Apple marketed the iPhone by saying something like, 'It's not the mobile Internet, it's the Internet on your phone,'" he said.

Across the Atlantic, the iPhone launched in Britain and AdMob immediately noticed impressions. In fact, the iPhone represented 0.3 percent of AdMob's British traffic in November only a month after its launch.

In other markets, India and South Africa continue to be exceptionally strong for the mobile Internet.

"Both are important markets for new mobile sites and services," Mr. Spero said.

AdMob serves graphical banner and text link ads on mobile Web pages for more than 2,000 publishers. The company has served more than 12 billion ads since launching last January. It currently serves more than 1.7 billion ads each month.

For each ad served, AdMob uses handset and carrier data, which helps with demographic, device and carrier targeting for advertisers.

The AdMob Mobile Metrics Report for November shows that AdMob Network impressions were up 4.5 percent to 1,722,213,245 compared with 1,648,546,800 for October. Western Europe and North America led the growth.

The top devices in AdMob's four key markets remained the same month-over-month: the Motorola KRZR in the U.S., the Nokia 6030 in India, the Motorola v360 in South Africa and the SonyEriccson K800i in Britain.

"The Nokia N series is showing strong growth in European markets and India," Mr. Spero said.

AdMob is continuing to monitor the growth of iPhone impressions. U.S. iPhone impressions grew from 1,658,008 in September to 4,816,701 in October and 6,646,601 in November.

"The iPhone dramatically overindexes on usage share compared with unit share," the AdMob Mobile Metrics Report said.