AdMob has released their latest network metrics report, with AdMob seeing 6.6 billion requests overall for the month of February.

This report also focuses on smartphones, where the iPhone is now seen as having 33% of worldwide smartphone traffic (50% in the US), and with Android representing 5% of the market.

Regarding other smartphone devices, the BlackBerry Curve is now the number one RIM product, having overtaken the Blackberry Pearl. The BlackBerry Storm is the number one device on Verizon with 14 percent of requests.

The report also looks at market share of each operating system. This is very important to keep track of for the burgeoning mobile applications market. Although Symbian is still the market leader, their lead seems to be rapidly eroding because of the iPhone.

AdMob also points out an important difference in the age of these operating systems. Symbian and Windows Mobile have a significant percentage of devices running older versions of their OS. This may cause a problem later in the year as these devices many not have access to their application stores when they launch. In contrast, the iPhone and RIM products are using more up-to-date software so they can fully utilize their app stores.

The report also presents data from a number of key markets, including US, UK, India, Indonesia, Phillippines, and South Africa. It is clear that over the past year the Asia market was very hot, but then cooled off a bit – at least in terms of AdMob served mobile ads.